By
New variants of the coronavirus are all slightly different from the original strain that vaccines were based on, so immunity to variants may be different.
Alexey Solodovnikov, Valeria Arkhipova/WikimediaCommons, CC BY-SA
4. What about the omicron variant?
The preliminary data about omicron and vaccines is coming in quickly and is revealing lower vaccine effectiveness. Best estimates suggest vaccines are around 30%-40% effective at preventing infections and 70% effective at preventing severe disease.
A preprint study – one not formally reviewed by other scientists yet – that was conducted in Germany found that antibodies in blood collected from people fully vaccinated with Moderna and Pfizer showed reduced efficacy in neutralizing the omicron variant. Other small preprint studies in South Africa and England showed a significant decrease in how well antibodies target the omicron variant. More breakthough infections are expected, with decreased immune system ability to recognize omicron compared with other variants.
5. Do boosters boost immunity against omicron?
Initial data reinforces that a third dose would help boost immune response and protection against omicron, with estimates of 70%-75% effectiveness.
Pfizer has reported that people who have received two doses of its vaccine are susceptible to infection from omicron, but that a third shot improves antibody activity against the virus. This was based on lab experiments using the blood of people who have received the vaccine.
Booster doses can increase the amount of antibodies and the ability of a person’s immune system to protect against omicron. However, unlike the U.S., much of the world does not have access to booster doses.
6. What does this all mean?
Despite the lowered effectiveness of vaccines against omicron, it is clear that vaccines do work and are among the greatest public health achievements. Vaccines have varying levels of effectiveness and are still useful. The flu vaccine is usually 40%-60% effective and prevents illness in millions of people and hospitalizations in more than 100,000 people in the U.S. annually.
Finally, vaccines protect not only those who are vaccinated, but those who can’t get vaccinated as well. Vaccinated people are less likely to spread COVID-19, which reduces new infections and offers protection to society overall.
[Get The Conversation’s most important coronavirus headlines, weekly in a science newsletter]
Melissa Hawkins, Professor of Public Health, American University
This article is republished from The Conversation under a Creative Commons license. Read the original article.