Should You Get New COVID-19 Booster to Fight Omicron?

Medical professionals praised the advantages of the newly developed mRNA COVID-19 vaccinations in December 2020, noting that formulations might be easily modified to keep up with a rapidly evolving virus. The time has here, at last.

Two revised boosters were approved by the FDA and recommended by the CDC in the fall of 2022. The emphasis of the boosters is on two different Omicron kinds called BA.4 and BA.5.

Death and severe sickness from COVID-19 can be avoided with the initial mRNA coronavirus vaccinations, but the virus has adapted, so breakthrough infections and reinfections are more likely now.

Both the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have given their blessing to the use of two revised boosters (one by Pfizer-BioNTech and the other by Moderna) in infants and young children as young as six months.

Is This Booster Different?

This new booster is a bivalent vaccination, which means that it protects against the coronavirus by including two messenger RNA (mRNA) components. This is a crucial point of differentiation. The BA.4 and BA.5 Omicron subvariant lineages are the targets of one half of the vaccine, while the other half is designed to protect against the original strain. It is anticipated that these lineages will continue to circulate throughout the fall and winter.

Is the Booster Safe?

The findings on the safety and effectiveness of the original COVID-19 mRNA vaccines, in addition to the trials of the new formulation in mice, were used as the basis for the authorization of the vaccinations by the relevant regulatory agencies. The regulatory bodies also considered data from human trials conducted by Pfizer and Moderna of a similar reformulation, which was directed at an earlier version of Omicron known as BA.1.

Pfizer provided updated clinical trial data in November, showing that the bivalent booster's safety and tolerability in human adults remained favorable and similar to its original COVID-19 vaccine. These findings were made public in November. Similarly, Moderna stated that its human trials did not reveal any new safety issues compared to its monovalent vaccine.

How Effective are the new Boosters?

The effectiveness of the monovalent vaccine against hospitalization was only 25%, but the efficacy of the bivalent vaccine against hospitalization was 58.7%. The monovalent vaccine was only 24.9% effective against infection, but the bivalent vaccine was 61.8% effective against the disease. The research was carried out when the Omicron BQ.1 and BQ.1.1 viruses were active in the population. It used data collected from adults and children aged 12 and older registered in North Carolina's vaccine registry. Before those subvariants spread, the bivalent vaccination was produced and administered.

In the meantime, another study investigated how effective the bivalent vaccine was against the more current Omicron subvariants XBB and XBB.1.5. According to the findings of the study, the effectiveness of the bivalent vaccine against BA.5 remained comparable in individuals who had previously received between two and four doses of the monovalent vaccine for at least the first three months following vaccination. This was the case in participants who had previously received the monovalent vaccine.

The gap Between two Boosters

Two months was determined to be the minimum amount of time that must pass by the FDA. Yet, several of the experts we consulted suggested that we hold off for a while longer. Some medical professionals believe that a longer interval of up to six months should be allowed before the next booster shot is administered. This is because someone who recently received a booster shot already has more circulating antibodies to combat viruses. Antibodies decrease in number with time, therefore, obtaining a subsequent trial too soon after the first one will not provide a significant additional advantage.

Can you Benefit From a Booster if you've Recently Recovered From COVID?

Imagine you were just told you had COVID-19. In such situation, you may want to wait three months from the onset of symptoms or, if you didn't have any symptoms, the day you got the positive test result before getting your next vaccination. According to several studies, allowing more time between an infection and a vaccination may result in a better immune response.

Although conceivable, reinfection is less likely to occur in the weeks and months following the initial infection. However, several considerations should be taken into account before making a decision regarding whether to get vaccinated, including the individual's risk of contracting a serious illness and the COVID-19 prevalence rate in the community.

Are These Updated Boosters more Effective?

Based on studies involving over 1,400 persons who received either a bivalent vaccination (containing a component of an omicron strain linked to BA.4 and BA.5) or a monovalent injection, the FDA assessed the immunogenicity (the immune response induced by a vaccine) and safety data of the revised boosters. One of the omicron strains linked to BA.4 and BA.5 was included in the bivalent vaccination.

An omicron strain related to BA.4 and BA.5 was used to develop at least part of the bivalent vaccine (with only a component of the original strain of the virus). Those who got both doses of the vaccine exhibited a substantially stronger immune response to the omicron strain than those who had only received one dose. This finding suggests that the bivalent vaccine may be more effective than the monovalent vaccine.

Also, the businesses provided data from trials conducted on mice which showed that the improved booster caused an overall better response to omicron variations in comparison to previous doses. It is anticipated that more extensive clinical tests on humans will get underway very shortly.

Early in the month of November, Pfizer disclosed the findings of a study that demonstrated that its improved bivalent COVID-19 booster produced approximately four times the level of antibodies capable of combating Omicron when compared to the company's initial vaccine in individuals aged 55 and older. Pfizer has stated that it is also evaluating how effective the vaccine is against newly discovered omicron subvariants.

Yet, it was discovered that the modified doses gave protection that was comparable to that of the already available vaccines.

Updated on: 31-Mar-2023


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