Vaccines continue to evolve, with new developments that could impact public health in significant ways. Three major updates in vaccine research are worth noting.
Norovirus: Progress Toward a Vaccine
While respiratory viruses often dominate discussions, norovirus has been a major concern this winter. More than 100 outbreaks have been reported weekly since Christmas—two to three times the usual number. This highly contagious virus causes severe vomiting and diarrhea, affecting over 700 million people worldwide each year.
Until now, preventing norovirus has been difficult due to the diversity of its genotypes. However, recent research has made progress in the search for a vaccine. One study has shown promising results for an oral vaccine, while another has identified ways to target multiple norovirus strains.
A new vaccine tablet has demonstrated an ability to generate antibodies in the blood, saliva, and mucous lining of the nose, as well as in the intestine. The immune response included activation of pathogen-fighting T and B cells, which could migrate to mucosal tissues. This broader immune response may be key to addressing norovirus infections effectively.
Other norovirus vaccine candidates are in development, including ones from different pharmaceutical companies. Although a vaccine is still a few years away, it could have the greatest impact on young children in low- and middle-income countries, where norovirus-related mortality is highest.
COVID-19: The Latest Vaccine Offers Moderate Protection
Recent data indicate that the current COVID-19 vaccine is providing moderate protection. Midseason analysis shows a 33% effectiveness against adult emergency room or urgent care visits due to COVID-19, slightly higher than the previous season’s estimated 25% effectiveness. Among older adults without immune system impairments, the vaccine was 45% effective against hospitalization, while effectiveness for immunocompromised older adults was 40%.
Several factors may have influenced these numbers, including a strong COVID-19 presence during the summer, which may have provided many individuals with some natural immunity. Additionally, the virus has mutated to become more contagious but less severe, which may have impacted vaccine performance.
Although the effectiveness rate might seem low, experts emphasize that the vaccine still provides valuable protection, particularly for those with chronic health conditions. It can reduce the severity of illness and the risk of complications. Vaccination rates, however, remain relatively low, with only 23% of adults receiving the latest COVID-19 shot, compared to 45% for the flu vaccine.
HPV: Vaccine Significantly Reduces Cervical Cancer Risk
The first group of girls vaccinated against human papillomavirus (HPV) are now in their early to mid-20s, and early data show that they are 80% less likely to develop precancerous lesions of the cervix compared to previous generations. This suggests that the vaccine could have a dramatic impact on reducing cervical cancer cases in the future.
HPV is extremely common, with nearly all sexually active individuals contracting at least one type of the virus during their lifetime. The vaccine, which is recommended for boys and girls starting at ages 11 or 12, has been shown to prevent 90% of cancers caused by HPV, including cervical cancer and nearly all cases of genital warts.
Current estimates suggest that about 39% of children ages 9 to 17 have received at least one dose of the HPV vaccine. Vaccination rates tend to be higher among children with private insurance or Medicaid, while those without insurance are significantly less likely to receive it.
These vaccine developments highlight the continuous advancements in protecting public health. While challenges remain, ongoing research and increased accessibility to vaccines can contribute to improved disease prevention worldwide.
