Development of Human Papillomavirus (HPV) Vaccines: A Review of Literature and Clinical Update.

The casual relationship concerning Human papillomaviruses (HPV) and cervical cancer is already established. Therefore, such HPV-associated malignancies might be prevented by prophylactic HPV vaccines. From 2009, two prophylactic HPV L1 Virus-Like Particle vaccines namely, Gardasil®; - quadrivalent (Merck) and Cervarix™ - bivalent (GlaxoSmithKline) are widely commercially available. By Aug 2014, 58 countries had introduced HPV vaccination in their national immunization program; this has led to numerous publications on safety and real world effectiveness. We have also seen long-term immunogenicity and efficacy data emerging. Data on cross-protection has also evolved. In clinical trials, it is observed that vaccinating adolescents results in higher immunological response than young adults hence to achieve best HPV vaccine efficacy it is advisable to immunize before the onset of sexual activity. Recently we have seen development of 2 dose vaccine schedule for adolescent, and emerging evidences even point that single dose of HPV vaccines can result in high efficacy, this observation is currently under consideration but if accepted will greatly impact vaccination coverage. In terms of safety, pregnancy registry did not find any unexpected patterns in fetal or maternal outcomes. This review only focuses on the efficacy and safety data of both Food and Drug Administration approved vaccines from clinical phase I to phase IV.

Pregnancy differentially impacts performance of latent tuberculosis diagnostics in a high-burden setting.

BACKGROUND: Targeted screening for latent TB infection (LTBI) in vulnerable populations is a recommended TB control strategy. Pregnant women are at high risk for developing TB and likely to access healthcare, making pregnancy an important screening opportunity in developing countries. The sensitivity of the widely-used tuberculin skin test (TST), however, may be reduced during pregnancy. METHODS: We performed a cross-sectional study comparing the TST with the QuantiFERON Gold In-tube (QGIT) in 401 HIV-negative women presenting antepartum (n = 154), at delivery (n = 148), or postpartum (n = 99) to a government hospital in Pune, India. A subset of 60 women enrolled during pregnancy was followed longitudinally and received both tests at all three stages of pregnancy. RESULTS: The QGIT returned significantly more positive results than the TST. Of the 401 women in the cross-sectional study, 150 (37%) had a positive QGIT, compared to 59 (14%) for the TST (p<0.005). Forty-nine (12%) did not have their TST read. Of 356 who had both results available, 46 (13%) were concordant positive, 91 (25%) were discordant (12 (3%) TST+/QGIT-; 79 (22%) TST-/QGIT+), and 206 (57%) concordant negative. Comparison by stage of pregnancy revealed that QGIT percent positivity remained stable between antepartum and delivery, unlike TST results (QGIT 31-32% vs TST 11-17%). Median IFN-γ concentration was lower at delivery than in antepartum or postpartum (1.66 vs 2.65 vs 8.99 IU/mL, p = 0.001). During postpartum, both tests had significantly increased positives (QGIT 31% vs 32% vs 52%, p = 0.01; TST 17% vs 11% vs 25%, p<0.005). The same trends were observed in the longitudinal subset. CONCLUSIONS: Timing and choice of LTBI test during pregnancy impact results. QGIT was more stable and more closely approximated the LTBI prevalence in India. But pregnancy stage clearly affects both tests, raising important questions about how the complex immune changes brought on by pregnancy may impact LTBI screening.