New COVID-19 Boosters Target Dominant Variant XBB.1.5, Long-Lasting Pan-Sarbecovirus Vaccines in Development
As COVID-19 continues to pose a threat, researchers are working tirelessly to develop effective solutions to combat the virus. With the emergence of new variants, such as the dominant omicron subvariant XBB.1.5, there is a need for booster shots to provide targeted protection. These booster shots are expected to be available by September or October, focusing on high-risk individuals over 65 years of age and those with underlying medical conditions.
However, concerns have been raised about the effectiveness of existing vaccines against emerging strains like EG.5, also known as Eris. The World Health Organization (WHO) classified EG.5 as a Virus of Interest on August 9, 2023, which led to some suggesting that waiting for an updated vaccine could be a better option than getting currently available boosters.
Experts contacted for this article have challenged this advice, stating that any vaccine is better than none, especially for older individuals and those at risk of severe COVID-19 symptoms. Waiting for an updated vaccine would only increase the risk of serious infection from the current variant. It’s important to note that the appearance of new variants has a limited lifespan, with each variant typically disappearing within three months.
COVID-19 is currently being managed through seasonal vaccination programs, as the immunity provided by vaccines does not last from year to year. Similar to flu vaccines, COVID-19 vaccines can be modified to target specific variants based on informed predictions of the most dominant strains in a given season.
Timing booster campaigns in early autumn, when respiratory virus infections are more frequent, offers the best protection during the worst time of the year for such infections. This approach helps alleviate the pressure on healthcare systems and reduces the chances of co-infections between influenza and COVID-19.
Vaccines do not necessarily prevent virus transmission but effectively protect against severe infections, particularly in individuals with hybrid immunity (both vaccination and prior infection). It is crucial for people to get vaccinated to enhance their protection against the virus.
In the short term, pharmaceutical companies like Moderna are developing booster vaccines that target specific variants like XBB strains and show effectiveness against emerging variants like EG.5 and FL1.5.1 (Fornax). However, these efforts focus on short-term solutions and do not establish long-lasting sterilizing immunity.
To achieve lasting and universal sterilizing immunity against SARS-CoV-2 and other beta coronaviruses, scientists are developing pan-sarbecovirus vaccines. These vaccines would provide comprehensive protection against a range of coronaviruses, including potential future pandemics.
Although promising candidates for pan-sarbecovirus vaccines are in development, the substantial costs involved hinder their progress. The first clinical use of such vaccines is expected in 2024. These groundbreaking vaccines have the potential to revolutionize the approach to coronavirus outbreaks, ensuring long-term protection and preventing the need for frequent booster shots.
In conclusion, while booster shots targeting specific variants like XBB.1.5 are on the horizon, it is important to prioritize getting vaccinated with the available vaccines. They provide crucial protection against severe COVID-19 symptoms, especially in high-risk individuals. Simultaneously, the development of pan-sarbecovirus vaccines offers hope for achieving lasting and universal protection against not only SARS-CoV-2 but also future potential coronaviruses. The ongoing efforts by scientists and researchers aim to ensure the world is better prepared for future pandemics.
