A mucosal adjuvant for the inactivated poliovirus vaccine

The eradication of poliovirus from the majority of the world has been achieved through the use of two vaccines: the inactivated poliovirus vaccine (IPV) and the live-attenuated oral poliovirus vaccine (OPV). Both vaccines are effective at preventing paralytic poliomyelitis, however, they also have significant differences. Most importantly for this work is the risk of revertant virus from OPV, the greater cost of IPV, and the low mucosal immunity induced by IPV. We and others have previously described the use of an alphavirus-based adjuvant that can induce a mucosal immune response to a co-administered antigen even when delivered at a non-mucosal site. In this report, we describe the use of an alphavirus-based adjuvant (GVI3000) with IPV. The IPV-GVI3000 vaccine significantly increased systemic IgG, mucosal IgG and mucosal IgA antibody responses to all three poliovirus serotypes in mice even when administered intramuscularly. Furthermore, GVI3000 significantly increased the potency of IPV in rat potency tests as measured by poliovirus neutralizing antibodies in serum. Thus, an IPV-GVI3000 vaccine would reduce the dose of IPV needed and provide significantly improved mucosal immunity. This vaccine could be an effective tool to use in the poliovirus eradication campaign without risking the re-introduction of revertant poliovirus derived from OPV.     

Characterization and standardization of Sabin based inactivated polio vaccine: proposal for a new antigen unit for inactivated polio vaccines

GMP-batches of Sabin-IPV were characterized for their antigenic and immunogenic properties. Antigenic fingerprints of Sabin-IPV reveal that the D-antigen unit is not a fixed amount of antigen but depends on antibody and assay type. Instead of the D-antigen unit we propose standardization of IPV based on a combination of protein amount for dose and D-antigenicity for quality of the vaccine. Although Sabin-IPV type 2 is less immunogenic than regular wild type IPV type 2, the immunogenicity (virus neutralizing titers) per microgram antigen for Sabin-IPV type 2 is in the same order as for wild type serotypes 1 and 3. The latter observations are in line with data from human trials. This suggests that a higher dose of Sabin-IPV type 2 to compensate for the lower rat immunogenicity may not be necessary.     

Persistence of protective anti-poliovirus antibody levels in 4-year-old children previously primed with Picovax®, a trivalent,aluminium-adjuvanted reduced dose inactivated polio vaccine

BackgroundTo meet the demand for effective and affordable inactivated polio vaccines (IPVs), a reduced dose, aluminium hydroxide (Al(OH)₃)-adjuvanted IPV vaccine was developed (IPV-Al, Picovax®) and evaluated in clinical trials. The present trial is an extension of two previous trials (a primary and a booster trial). The aim was to evaluate the persistence of seroprotective antibodies (poliovirus type-specific antibody titre ≥ 8) in 4-year-old children who previously received IPV–Al as primary and booster vaccine doses and to determine the potential booster response and safety profile of an additional dose of IPV-Al.MethodsChildren participating in the two previous trials were invited to receive one additional dose of IPV-Al at 4 years of age (2.5 years after the booster dose) and to have their blood samples collected to measure the pre- and post-vaccination antibody titres. Systemic adverse events (AEs) and local reactogenicity were recorded.ResultsAt study entry, the seroprotection rates were 89.2%, 100% and 91.1% against poliovirus type 1, 2 and 3, respectively. The additional vaccination with IPV-Al boosted the level of poliovirus type 1, 2 and 3 antibodies to above the seroprotection threshold for all but one subject, i.e., 99.4% for type 1 and 100% for types 2 and 3. The additional dose induced a robust booster response of a 26.3-, 13.9- and 30.9-fold increase in titre for poliovirus types 1, 2 and 3, respectively. The vaccine was well tolerated, with only mild and transient AEs reported.ConclusionsThe present trial demonstrated that the primary vaccination with an aluminium-adjuvanted reduced dose IPV induced a persistent immune memory as evidenced by the robust anamnestic response when the subjects were re-exposed to the antigen 2.5 years after the last dose. Thus, the IPV-Al is an efficient and safe addition to increase the availability of inactivated polio vaccines globally. (ClinicalTrials.gov reg no. NCT04448132).     

Intradermal fractional dose inactivated polio vaccine: a review of the literature

Oral polio vaccine (OPV) will likely be insufficient to completely eradicate polio due to its propensity to mutate into neurovirulent forms and its inability to produce adequate immunity in certain areas of the world. Inactivated polio vaccine (IPV), a killed vaccine which therefore cannot mutate, may be more effective than OPV in certain populations, and will likely be required for global polio eradication. However, the high cost of IPV is prohibitive in many areas of the world. Intradermal administration has the potential to lower the dose, and thus the cost, of IPV. This article reviews the clinical studies to date on intradermal fractional dose polio vaccination. We conclude that intradermal IPV vaccination shows potential as a means to reduce the cost and increase the ease of administration of IPV, but that additional research is needed to determine the optimal fractional dose, timing, and role of adjuvants in intradermal IPV vaccination as well as the clinical significance of different antibody titers above the threshold for seroconversion.     

sIPV process development for costs reduction

Polio is expected to be eradicated within only a few years from now. Upon polio eradication, the use of oral polio vaccines, which can cause circulating and virulent vaccine derived polio viruses, will be stopped. From this moment onwards, inactivated polio vaccines (IPV) will be used for worldwide vaccination against polio. An increased demand for IPV is thus anticipated. As a result, process development studies regarding the IPV production process, developed in the 1960s, have intensified. Studies on yield optimization aiming at costs reduction as well as the use of alternative polio viruses, which are more biosafe for manufacturing, are actual. Here our strategy to setup a new IPV production process using attenuated Sabin polio virus strains is presented. Moreover, aspects on reduction of the costs of goods and the impact of process optimization on sIPV costs are reviewed.     

Assessing the immunogenicity of three different inactivated polio vaccine schedules for use after oral polio vaccine cessation,an open label,phase IV,randomized controlled trial

BackgroundAfter global oral poliovirus vaccine (OPV) cessation, the Strategic Advisory Group of Experts on Immunization (SAGE) currently recommends a two-dose schedule of inactivated poliovirus vaccine (IPV) beginning ≥14-weeks of age to achieve at least 90% immune response. We aimed to compare the immunogenicity of three different two-dose IPV schedules started before or at 14-weeks of age.MethodsWe conducted a randomized, controlled, open-label, inequality trial at two sites in Dhaka, Bangladesh. Healthy infants at 6-weeks of age were randomized into one of five arms to receive two-dose IPV schedules at different ages with and without OPV. The three IPV-only arms are presented: Arm C received IPV at 14-weeks and 9-months; Arm D received IPV at 6-weeks and 9-months; and Arm E received IPV at 6 and 14-weeks. The primary outcome was immune response defined as seroconversion from seronegative (<1:8) to seropositive (≥1:8) after vaccination, or a four-fold rise in antibody titers and median reciprocal antibody titers to all three poliovirus types measured at 10-months of age.FindingsOf the 987 children randomized to Arms C, D, and E, 936 were included in the intention-to-treat analysis. At 10-months, participants in Arm C (IPV at 14-weeks and 9-months) had ≥99% cumulative immune response to all three poliovirus types which was significantly higher than the 77–81% observed in Arm E (IPV at 6 and 14-weeks). Participants in Arm D (IPV at 6-weeks and 9-months) had cumulative immune responses of 98–99% which was significantly higher than that of Arm E (p value < 0.0001) but not different from Arm C.InterpretationResults support current SAGE recommendations for IPV following OPV cessation and provide evidence that the schedule of two full IPV doses could begin as early as 6-weeks.     

Co-administration study in South African infants of a live-attenuated oral human rotavirus vaccine (RIX4414) and poliovirus vaccines

A double-blind, placebo-controlled phase II trial (e-Track 444563-014/NCT00346892) was conducted in South Africa to evaluate the co-administration of RIX4414 (live-attenuated human G1P[8] rotavirus vaccine) and oral poliovirus vaccine (OPV) administered simultaneously. Healthy infants (n=450) were randomized into three groups (RIX4414+OPV, RIX4414+IPV or Placebo+OPV) to receive two oral doses of RIX4414/placebo with OPV or IPV using two vaccination schedules (6-10 weeks and 10-14 weeks). Serum anti-rotavirus IgA antibodies (ELISA) and neutralizing antibodies (micro-neutralization assay) to poliovirus serotypes 1, 2 and 3 were measured. Co-administration of RIX4414 with OPV did not result in a decrease in the high sero-protection rates against poliovirus serotypes 1, 2 and 3 detected after the third OPV dose (98-100%). The anti-rotavirus IgA antibody sero-conversion rates were higher for the 10-14 weeks schedule (55-61%) compared to the 6-10 weeks schedule (36-43%). Solicited symptoms were reported at similar rates between RIX4414 and placebo groups and no serious adverse events related to RIX4414 were reported. This study provided evidence that RIX4414 can be co-administered with routine EPI immunizations including OPV and that two doses of RIX4414 were well tolerated and immunogenic in South African infants.     

Immunogenicity of Infanrix™ hexa administered at 3, 5 and 11 months of age

A pooled analysis of data from four vaccination studies conducted in Europe was undertaken to assess the immunogenicity of Infanrix™ hexa (DTPa–HBV–IPV/Hib, GlaxoSmithKline Biologicals) when administered in a total of 702 healthy infants at 3, 5 and 11–12 months of age. One month after dose 2, between 96.3% and 100% of subjects had seroprotective antibodies against diphtheria, tetanus, hepatitis B and poliovirus types 1, 2 and 3; 91.7% against Hib and ≥99.0% were seropositive for each pertussis antigen. One month after the third dose, 98.9–100% of subjects were seroprotected/seropositive for all vaccine antigens. Geometric mean antibody concentrations/titres for each vaccine antigen increased by 6.7–52.9 fold after the third vaccine dose. No serious adverse events in DTPa–HBV–IPV/Hib recipients were vaccine related. Infanrix™ hexa induces an adequate immune response after 2-dose primary plus booster doses when administered according to a 3, 5 and 11 months schedule.     

Inactivated polio vaccination using a microneedle patch is immunogenic in the rhesus macaque

The phased replacement of oral polio vaccine (OPV) with inactivated polio vaccine (IPV) is expected to significantly complicate mass vaccination campaigns, which are an important component of the global polio eradication endgame strategy. To simplify mass vaccination with IPV, we developed microneedle patches that are easy to administer, have a small package size, generate no sharps waste and are inexpensive to manufacture. When administered to rhesus macaques, neutralizing antibody titers were equivalent among monkeys vaccinated using microneedle patches and conventional intramuscular injection for IPV types 1 and 2. Serologic response to IPV type 3 vaccination was weaker after microneedle patch vaccination compared to intramuscular injection; however, we suspect the administered type 3 dose was lower due to a flawed pre-production IPV type 3 analytical method. IPV vaccination using microneedle patches was well tolerated by the monkeys. We conclude that IPV vaccination using a microneedle patch is immunogenic in rhesus macaques and may offer a simpler method of IPV vaccination of people to facilitate polio eradication.     

Immunogenicity to poliovirus type 2 following two doses of fractional intradermal inactivated poliovirus vaccine: A novel dose sparing immunization schedule

IntroductionThe polio eradication endgame strategic plan calls for the sequential removal of Sabin poliovirus serotypes from the trivalent oral poliovirus vaccine (tOPV), starting with type 2, and the introduction of ≥1 dose of inactivated poliovirus vaccine (IPV), to maintain an immunity base against poliovirus type 2. The global removal of oral poliovirus type 2 was successfully implemented in May 2016. However, IPV supply constraints has prevented introduction in 21 countries and led to complete stock-out in >20 countries.MethodsWe conducted a literature review and contacted corresponding authors of recent studies with fractional-dose IPV (fIPV), one-fifth of intramuscular dose administered intradermally, to conduct additional type 2 immunogenicity analyses of two fIPV doses compared with one full-dose IPV.ResultsFour studies were identified that assessed immunogenicity of two fIPV doses compared to one full-dose IPV. Two fractional doses are more immunogenic than 1 full-dose, with type 2 seroconversion rates improving between absolute 19–42% (median: 37%, p < 0.001) and relative increase of 53–125% (median: 82%), and antibody titer to type 2 increasing by 2–32-fold (median: 10-fold). Early age of administration and shorter intervals between doses were associated with lower immunogenicity.DiscussionOverall, two fIPV doses are more immunogenic than a single full-dose, associated with significantly increased seroconversion rates and antibody titers. Two fIPV doses together use two-fifth of the vaccine compared to one full-dose IPV. In response to the current IPV shortage, a schedule of two fIPV doses at ages 6 and 14 weeks has been endorsed by technical oversight committees and has been introduced in some affected countries.     

Immunogenicity and safety of sabin-strain based inactivated poliovirus vaccine replacing salk-strain based inactivated poliovirus vaccine: An innovative application of different strain-IPVs replacement

BackgroundA domestic Sabin strain-based inactivated poliovirus vaccine (Sabin IPV) was approved by China Food and Drug Administration in 2017 as a replacement for the Salk strain-based inactivated poliovirus vaccine (Salk IPV) that has been in use in China for over 10 years. The present post-marketing trial was implemented in China to assess the immunogenicity and safety of replacing the Salk IPV with the Sabin IPV in the last two immunizations of the standard three-dose schedule.MethodsWe conducted a randomized, controlled clinical trial with two groups that received three doses of IPVs at the age of 2, 3, and 4 months: the Salk-Sabin-Sabin group and the Salk-Salk-Salk group. Blood samples were collected before vaccination and 30–40 days after the third dose of vaccination. The seroconversion rates and antibody geometric mean titers (GMTs) were calculated and analyzed to evaluate immunogenicity. The safety of both immunization schedules was also monitored and analyzed.ResultsOf 360 recruited healthy infants, all three IPV doses were administered and blood collection was completed in 330 infants. All participants (100%) in both groups were seropositive for all three poliovirus types after the last vaccination. There were significant differences between the two groups (P < 0.001) in the GMTs for antibodies against poliovirus types 1 and 2, but no significant difference was observed for antibodies against type 3 (P = 0.009). A non-inferiority t-test showed that the post-immunization GMTs for all three types in the Salk-Sabin-Sabin group were not inferior to those in the Salk-Salk-Salk group (P < 0.001). Safety assessment indicated that there was no significant difference in the incidence of all adverse events between the two groups (P = 0.806).ConclusionsThe Salk-Sabin-Sabin IPV immunization schedule is not inferior to the Salk-Salk-Salk IPV schedule in terms of both immunogenicity and safety.Clinical trial number: NCT04051736.     

Immune responses after fractional doses of inactivated poliovirus vaccine using newly developed intradermal jet injectors: A randomized controlled trial in Cuba

IntroductionThe World Health Organization recommends that, as part of the new polio endgame, a dose of inactivated poliovirus vaccine (IPV) be introduced by the end of 2015 in all countries using only oral poliovirus vaccine (OPV). Administration of fractional dose (1/5th of full dose) IPV (fIPV) intradermally may reduce costs, but its administration is cumbersome with BCG needle and syringe. We evaluated performance of two newly developed intradermal-only jet injectors and compared the immune response induced by fIPV with that induced by full-dose IPV.MethodsChildren between 12 and 20 months of age, who had previously received two doses of OPV, were enrolled in Camaguey, Cuba. Subjects received a single dose of IPV (either full-dose IPV intramuscularly with needle and syringe or fIPV intradermally administered with one of two new injectors or with BCG needle or a conventional needle-free injector). Serum was tested for presence of poliovirus neutralizing antibodies on day 0 (pre-IPV) and on days 3, 7 and 21 (post-vaccination).ResultsComplete data were available from 74.2% (728/981) subjects. Baseline median antibody titers were 713, 284, and 113 for poliovirus types 1, 2, and 3, respectively. Seroprevalence at study end were similar across the intervention groups (≥94.8%). The immune response induced with one new injector was similar to BCG needle and to the conventional injector; and superior to the other new injector. fIPV induced significantly lower boosting response compared to full-dose IPV. No safety concerns were identified.InterpretationOne of the two new injectors demonstrated its ability to streamline intradermal fIPV administration, however, further investigations are needed to assess the potential contribution of fIPV in the polio endgame plan.     

CpG oligodeoxynucleotides are a potent adjuvant for an inactivated polio vaccine produced from Sabin strains of poliovirus

Poliovirus transmission is controlled globally through world-wide use of a live attenuated oral polio vaccine (OPV). However, the imminence of global poliovirus eradication calls for a switch to the inactivated polio vaccine (IPV). Given the limited manufacturing capacity and high cost of IPV, this switch is unlikely in most developing and undeveloped countries. Adjuvantation is an effective strategy for antigen sparing. In this study, we evaluated the adjuvanticity of CpG oligodeoxynucleotides (CpG-ODN) for an experimental IPV produced from Sabin strains of poliovirus. Our results showed that CpG-ODN, alone or in combination with alum, can significantly enhance both the humoral and cellular immune responses to IPV in mice, and, consequently, the antigen dose could be reduced substantially. Therefore, our study suggests that the global use of IPV could be facilitated by using CpG-ODN or other feasible adjuvants.     

Polio vaccination coverage and seroprevalence of poliovirus antibodies after the introduction of inactivated poliovirus vaccines for routine immunization in Japan

In Japan, the oral poliovirus vaccine (OPV) was changed to 2 types of inactivated poliovirus vaccine (IPV), the standalone conventional IPV (cIPV) and the Sabin-derived IPV combined with diphtheria-tetanus-acellular pertussis vaccine (DTaP-sIPV), for routine immunization in 2012. We evaluated polio vaccination coverage and the seroprevalence of poliovirus antibodies using data from the National Epidemiological Surveillance of Vaccine-Preventable Diseases (NESVPD) from 2011 to 2015. Several years before the introduction of IPV in 2012, OPV administration for children was refused by some parents because of concerns about the risk of vaccine-associated paralytic poliomyelitis. Consequently, in children aged <1?years who were surveyed in 2011–2012, polio vaccination coverage (45.0–48.8%) and seropositivity rates for poliovirus (type 1: 51.7–65.9%, type 2: 48.3–53.7%, and type 3: 15.0–29.3%) were decreased compared to those surveyed in 2009. However, after IPV introduction, the vaccination coverage (95.5–100%) and seropositivity rates (type 1: 93.2–96.6%, type 2: 93.1–100%, and type 3: 88.6–93.9%) increased among children aged <1?years in 2013–2015. In particular, seropositivity rates and geometric mean titers (GMTs) for poliovirus type 3 in <5-year-old children who received 4 doses of IPV (98.5% and 247.4, respectively) were significantly higher than in those who received 2 doses of OPV (72.5% and 22.9, respectively). Furthermore, in <5-year-old children who received 4 doses of either DTaP-sIPV or cIPV, the seropositivity rates and the GMTs for all 3 types of poliovirus were similarly high (96.5–100% and 170.3–368.8, respectively). Our findings from the NESVPD demonstrate that both the vaccination coverage and seropositivity rates for polio remained high in children after IPV introduction.     

The global introduction of inactivated polio vaccine can circumvent the oral polio vaccine paradox

This literature review identifies the factors that influence the decision to introduce inactivated polio vaccine (IPV) in developing countries as opposed to the policy of vaccine cessation. Attenuated viruses in the oral polio vaccine (OPV) can replicate, revert to neurovirulence and become transmissible circulating vaccine-derived polioviruses (cVDPVs), preventing use of the vaccine in the post-eradication era. This literature review identifies (1) risks of complete cessation of vaccination, (2) barriers and (3) solutions for the introduction of IPV in developing countries. The reviewed literature favours to circumvent the so-called “OPV paradox” by global introduction of IPV.     

Safety,tolerability, and immunogenicity of inactivated poliovirus vaccine with or without E.coli double mutant heat-labile toxin (dmLT) adjuvant in healthy adults; a phase 1 randomized study

BackgroundInactivated trivalent poliovirus vaccine (IPV) induces humoral immunity, which protects against paralytic poliomyelitis but does not induce sufficient mucosal immunity to block intestinal infection. We assessed the intestinal immunity in healthy adults in Belgium conferred by a co-formulation of IPV with the mucosal adjuvant double mutant Labile Toxin (dmLT) derived from Escherichia coli.MethodsHealthy fully IPV-vaccinated 18–45-year-olds were randomly allocated to three groups: on Day 1 two groups received one full dose of IPV (n = 30) or IPV + dmLT (n = 30) in a blinded manner, and the third received an open-label dose of bivalent live oral polio vaccine (bOPV types 1 and 3, n = 20). All groups received a challenge dose of bOPV on Day 29. Participants reported solicited and unsolicited adverse events (AE) using study diaries. Mucosal immune responses were measured by fecal neutralization and IgA on Days 29 and 43, with fecal shedding of challenge viruses measured for 28 days. Humoral responses were measured by serum neutralizing antibody (NAb).ResultsSolicited and unsolicited AEs were mainly mild-to-moderate and transient in all groups, with no meaningful differences in rates between groups. Fecal shedding of challenge viruses in both IPV groups exceeded that of the bOPV group but was not different between IPV and IPV + dmLT groups. High serum NAb responses were observed in both IPV groups, alongside modest levels of fecal neutralization and IgA.ConclusionsAddition of dmLT to IPV administered intramuscularly neither affected humoral nor intestinal immunity nor decreased fecal virus shedding following bOPV challenge. The tolerability of the dose of dmLT used in this study may allow higher doses to be investigated for impact on mucosal immunity.Registered on ClinicalTrials.gov - NCT04232943.     

Development and introduction of inactivated poliovirus vaccines derived from Sabin strains in Japan

During the endgame of global polio eradication, the universal introduction of inactivated poliovirus vaccines is urgently required to reduce the risk of vaccine-associated paralytic poliomyelitis and polio outbreaks due to wild and vaccine-derived polioviruses. In particular, the development of inactivated poliovirus vaccines (IPVs) derived from the attenuated Sabin strains is considered to be a highly favorable option for the production of novel IPV that reduce the risk of facility-acquired transmission of poliovirus to the communities. In Japan, Sabin-derived IPVs (sIPVs) have been developed and introduced for routine immunization in November 2012. They are the first licensed sIPVs in the world. Consequently, trivalent oral poliovirus vaccine was used for polio control in Japan for more than half a century but has now been removed from the list of vaccines licensed for routine immunization. This paper reviews the development, introduction, characterization, and global status of IPV derived from attenuated Sabin strains.     

Gap in the prevalence of neutralising antibodies to polioviruses in antenatal women in southern India

With the disappearance of circulating wild poliovirus and improved sanitation, protective antibody levels may wane over time following oral poliovirus vaccine (OPV) administration. This study evaluated the seroprevalence of neutralising antibodies to vaccine polioviruses among young Indian women who had received at least three doses of OPV as primary immunisation. Of 60 women studied, 27 (45%) had antibody titres of <1:8 to one or more polioviruses, with the lowest levels for poliovirus types 3 and 1. These findings represent a possible immunity gap and this needs to be confirmed with further studies, which could include a challenge with vaccine virus.     

Intranasal and sublingual delivery of inactivated polio vaccine

Polio is on the brink of eradication. Improved inactivated polio vaccines (IPV) are needed towards complete eradication and for the use in the period thereafter. Vaccination via mucosal surfaces has important potential advantages over intramuscular injection using conventional needle and syringe, the currently used delivery method for IPV. One of them is the ability to induce both serum and mucosal immune responses: the latter may provide protection at the port of virus entry.The current study evaluated the possibilities of polio vaccination via mucosal surfaces using IPV based on attenuated Sabin strains. Mice received three immunizations with trivalent sIPV via intramuscular injection, or via the intranasal or sublingual route. The need of an adjuvant for the mucosal routes was investigated as well, by testing sIPV in combination with the mucosal adjuvant cholera toxin.Both intranasal and sublingual sIPV immunization induced systemic polio-specific serum IgG in mice that were functional as measured by poliovirus neutralization. Intranasal administration of sIPV plus adjuvant induced significant higher systemic poliovirus type 3 neutralizing antibody titers than sIPV delivered via the intramuscular route. Moreover, mucosal sIPV delivery elicited polio-specific IgA titers at different mucosal sites (IgA in saliva, fecal extracts and intestinal tissue) and IgA-producing B-cells in the spleen, where conventional intramuscular vaccination was unable to do so. However, it is likely that a mucosal adjuvant is required for sublingual vaccination. Further research on polio vaccination via sublingual mucosal route should include the search for safe and effective adjuvants, and the development of novel oral dosage forms that improve antigen uptake by oral mucosa, thereby increasing vaccine immunogenicity. This study indicates that both the intranasal and sublingual routes might be valuable approaches for use in routine vaccination or outbreak control in the period after complete OPV cessation and post-polio eradication.     

灭活脊髓灰质炎病毒疫苗在中国应用的咨询意见调查

目的从扩大免疫规划（Expanded Program on Immunization,EPI）专家认知,来探讨灭活脊髓灰质炎（脊灰）病毒疫苗（Inactivated Poliovirus Vaccine,IPV）在中国应用的相关问题,为制定脊灰疫苗免疫策略提供参考。方法以人口数多和疫苗需求量大为原则,在全国范围内选取7个省（自治区）,对30名EPI专家进行开放式问卷调查。结果50％的调查对象希望在2015年国家能将IPV纳入EPI,与世界卫生组织提出的{2013～2018年消灭脊灰终结战略计划》时间进度表同步,专家们一致认同在保证疫苗质量的前提下,应尽可能地降低疫苗成本,IPV可接受价格中位数为20元／剂（范围5～50元／剂）。实现IPV国产化势在必行,卫生行政等政府部门应尽快明确中国脊灰疫苗免疫策略和使用时间进度表,疾病预防控制中心依据卫生行政部门制定的免疫策略提供技术指导和支持,疫苗生产企业应加快IPV的研发、生产和上市。结论EPI专家一致赞同随着全球消灭脊灰的进程,中国逐步引入IPV是大势所趋。