Safety and immunogenicity of an Escherichia coli-produced bivalent human papillomavirus type 6/11 vaccine: A dose-escalation, randomized, double-blind, placebo-controlled phase 1 trial

Molecular dynamics simulation and purification of chimeric L1/L2 protein from human papillomavirus type 52 expressed in Escherichia coli BL21 (DE3)

The available prophylactic vaccines for human papillomavirus (HPV) in the market are only effective against specific types of HPV, rendering them ineffective for other types of HPV infections. The objective of this research is to investigate the stability of the recombinant protein constructed, namely chimeric L1/L2 protein from HPV type 52, with improved cross-neutralization ability. The 3D model, predicted using Alphafold, Robetta, I-Tasser, and refined with Galaxy Refinement, is validated using Ramachandran plot analysis. The stability is verified through molecular dynamics simulations, considering parameters such as RMSD, RMSF, Rg, and SASA, where stable conditions are observed. The chimeric L1/L2 protein from HPV type 52 is purified using affinity chromatography, and the His-tag is cleaved using SUMO protease to obtain pure chimeric protein with the size of ~ 55 kDa. Western blot analysis confirms binding to anti-L1 HPV type 52 polyclonal antibody. The obtained vaccine candidate can be utilized as an effective prophylactic vaccine against HPV.

Attitudes toward an HPV vaccine for condyloma acuminata and willingness to undergo vaccination among STD clinic attendees in China: Focus on STI prevention with HPV vaccine

BACKGROUND

Condyloma acuminata (CA) is a common, and recurrent sexually transmitted disease (STD) that greatly contributes to direct health care costs and has a substantial psychosocial impact. Human papillomavirus (HPV) vaccination (containing L1 protein for HPV types 6 and 11) effectively controls CA.

OBJECTIVES

We investigated attitudes toward the HPV vaccine for CA and willingness to undergo vaccination among STD clinic attendees in China.

METHODS

Attendees at STD clinics at two selected hospitals in Guangdong and Jiangsu Provinces from May to September 2017 were requested to complete a self-administered questionnaire for this cross-sectional study.

RESULTS

The participants' median age was 28 years (IQR: 24.0-34.0), and the sex ratio was balanced; 63.5% were from Guangdong, 36.5% were from Jiangsu, and 44.5% had a history of CA. The vaccine acceptance rate was high among the participants (85.8%,235/274) to whom the HPV vaccine for CA was available, especially among those who had heard of CA (89.0%, AOR = 3.14, 95% CI: 1.29-7.63, p = 0.0114). 95 (34.7%) of 274 participants had a positive attitude toward the HPV vaccine for CA. STD clinic attendees who had heard of the connection between HPV and CA (AOR = 2.56, 95% CI: 1.31-5.00, p = 0.0060), had heard of the HPV vaccines or cervical cancer vaccines (AOR = 1.90, 95% CI: 1.02-3.54, p = 0.0444) and had ever proactively discussed CA or the vaccine with others (AOR = 1.95, 95% CI:1.00-3.79, p = 0.0488) had better attitudes toward the HPV vaccine for CA. Over half of the participants (52.5%) expected the price of the HPV vaccine for CA to be under $90.

CONCLUSION

The acceptance of the HPV vaccine for CA was high among STD clinic attendees in China, and the participants' self-perceived knowledge of CA and HPV was associated with better attitudes toward the HPV vaccine for CA. Education to improve knowledge is vital for reducing vaccine hesitancy.

Rational design of a cross-type HPV vaccine through immunodominance shift guided by a cross-neutralizing antibody

In vaccine development, broadly or cross-type neutralizing antibodies (bnAbs or cnAbs) are frequently targeted to enhance protection. Utilizing immunodominant antibodies could help fine-tune vaccine immunogenicity and augment the precision of immunization strategies. However, the methodologies to capitalize on the attributes of bnAbs in vaccine design have not been clearly elucidated. In this study, we discovered a cross-type neutralizing monoclonal antibody, 13H5, against human papillomavirus 6 (HPV6) and HPV11. This nAb exhibited a marked preference for HPV6, demonstrating superior binding activity to virus-like particles (VLPs) and significantly higher prevalence in anti-HPV6 human serum as compared to HPV11 antiserum (90% vs. 31%). Through co-crystal structural analysis of the HPV6 L1 pentamer:13H5 complex, we delineated the epitope as spanning four segments of amino acids (Phe42-Ala47, Gly172-Asp173, Glu255-Val275, and Val337-Tyr351) on the L1 surface loops. Further interaction analysis and site-directed mutagenesis revealed that the Ser341 residue in the HPV6 HI loop plays a critical role in the interaction between 13H5 and L1. Substituting Ser341 with alanine, which is the residue type present in HPV11 L1, almost completely abolished binding activity to 13H5. By swapping amino acids in the HPV11 HI loop with corresponding residues in HPV6 L1 (Ser341, Thr338, and Thr339), we engineered chimeric HPV11-6HI VLPs. Remarkably, the chimeric HPV11-6HI VLPs shifted the high immunodominance of 13H5 from HPV6 to the engineered VLPs and yielded comparable neutralization titers for both HPV6 and HPV11 in mice and non-human primates. This approach paves the way for the design of broadly protective vaccines from antibodies within the main immunization reservoir.

Awareness and acceptance of HPV vaccination for condyloma acuminata among men who have sex with men in China

The dissemination of the fact that the human papillomavirus (HPV) vaccine can protect females as well as males is greatly beneficial for the control of condyloma acuminata (CA). We aimed to investigate the acceptance of the HPV vaccine for CA among men who have sex with men (MSM) in China. A cross-sectional online survey in the adult MSM population from 31 regions in China was carried out via WeChat in May 2017. Information on demographic characteristics, sexual behaviors, history of HIV and HPV infection, awareness of CA and HPV/CA vaccines, acceptance of CA vaccination, and behavioral intentions for vaccination were collected through a self-administered questionnaire. In total, 902 questionnaires were analyzed; the prevalence of CA was 13.3% (120/902), the HIV positivity rate was 15.1% (136/902), and the coinfection rate of HIV and CA was 3.9% (35/902). In the MSM population, the knowledge of CA and HPV/CA vaccines was poor, but the acceptance rate of the CA vaccine was high (85.1%, 768/902). Data indicated that MSM who had a history of anal intercourse (OR = 1.9), had heard of CA (OR = 2.9), knew the treatments for CA (OR = 2.0), had heard of HPV vaccines/cervical cancer vaccines (OR = 1.9), and received education about CA (OR = 1.9) were associated with the intention to use CA vaccines. With current moderate levels of CA and HPV/CA vaccine awareness, more emphasis should be placed on improving education and other behavioral interventions for high-risk populations such as MSM in China.