COVID-19 Booster Dose? Are all COVID-19 vaccine boosters safe?

COVID-19 Booster Dose? Are all COVID-19 vaccine boosters safe and effective?

What is a booster dose?

A booster dose is an additional dose of a vaccination given after the primer dose. A booster gives re-exposure to the immune-compromised antigen after the original vaccination. Its purpose is to restore resistance mechanisms against that antigen once memory for that antigen has deteriorated over time. If a patient takes a booster dosage but already has a protective antibody level, an Arthus response, a localized type of Type III hypersensitivity caused by high levels of IgG antibodies producing inflammation, may occur. The inflammation usually goes away on its own after a few days, but it might be prevented entirely by lengthening the interval between the main immunization and the booster dosage.

What is the COVID-19 vaccine?

A COVID19 vaccine is a vaccine designed to confer acquired immunity against the virus that causes coronavirus illness 2019 (COVID19), the severe acute respiratory syndrome coronavirus 2 (SARSCoV2). According to official statistics from national public health organizations, 9.37 billion doses of COVID19 vaccinations had been delivered worldwide as of January 7, 2022. More than 10 billion vaccine doses had been preordered by countries by December 2020, with approximately half of the doses purchased by high-income countries, which account for 14% of the global population.

What are COVID-19 vaccine boosters?

A COVID booster shot is an extra dose of a vaccination administered after the first injection(s)’ protection has begun to wane over time. After your immunity from the original dose(s) begins to diminish, you’ll usually need a booster shot. The booster is intended to help people retain their immunity for a longer period.

Who can get a COVID-19 vaccine booster?

A COVID-19 booster is recommended by the CDC if you are:

1. 18 or older and received both required doses of the Moderna vaccine at least six months ago
2. 16 or older and received both required doses of the Pfizer-BioNTech vaccine at least six months ago.
3. 18 or older and received the Janssen/Johnson & Johnson vaccine at least two months ago

Which boosters can you get?

1. If you received the Moderna vaccine, Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) are preferred in most situations
2. If you received the Pfizer-BioNTech vaccine, Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) are preferred in most situations. In addition, Teens 12–17 years old may only get a Pfizer-BioNTech COVID-19 vaccine booster.
3. If you received the Janssen/Johnson & Johnson vaccine, Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) are preferred in most* situations

COVID-19 vaccine boosters performance?

Regulatory authorities in numerous jurisdictions have approved booster vaccination and added it to the product labeling of BNT162b2, mRNA 1273, and Ad26.COV2.S. In addition, booster dosage clinical trial data is available for ChAdOx1-S [recombinant] and CoronaVac, COVID-19 vaccination BIBP, BBV152, and NVX-CoV2373 vaccines. To date, all investigations have shown a substantial anamnestic immunological response that reaches or exceeds peak antibody levels following the primary vaccination series, but there is inadequate data and follow-up to judge the reaction’s kinetics and longevity. Immunologically, both homologous and heterologous booster regimens are successful.

Since no correlate of protection has yet been identified, vaccination performance of these heterologous regimens cannot be predicted with high confidence based on the immune response. Vaccine efficacy statistics for a booster dose are increasingly being released from a growing number of countries, although follow-up time is still restricted. All of the trials show an improvement in infection resistance, illness mildness, as well as severe sickness and mortality.

Small-scale clinical trials and post-licensure data with limited follow-up are used in safety and reactogenicity research. They have a safety profile that is comparable to that seen after the second dosage in the main series. Regulatory agencies and advisory organizations have so determined that booster immunization has a favorable benefit-risk ratio at the individual level.

Are all COVID-19 vaccine boosters safe?

The current study enlisted 2,878 individuals from 18 study locations around the United Kingdom. The individuals had received two doses of either the Pfizer-BioNTech or Oxford-AstraZeneca vaccine and were at least 30 years old. Before getting their third booster shot, these people had received their second dose of the Oxford-AstraZeneca or Pfizer-BioNTech vaccine for at least 10 or 12 weeks, respectively. During the trial, the participants got any of the seven vaccinations indicated above as the third dosage. During the data analysis, the researchers divided the individuals into younger and older age groups. Participants in the younger group ranged in age from 30 to 69 years old, while those in the elder group were 70 and older. The scientists also tested the safety of half-doses of the Valneva, Pfizer-BioNTech, and Novavax vaccines, as well as the immunological response they elicited. A meningococcal conjugate vaccination was given to a control group. The participants were requested to keep a daily electronic journal to document any negative effects. During future visits to the study site, they analyzed the safety of the vaccine booster doses. With all vaccinations, the adverse effects noticed following the booster dosage were largely tolerable. The most prevalent negative effects were injection site soreness, headache, and weariness.

With some immunizations, the inflammatory side effects were more pronounced. Individuals under the age of 70 who were primed with two doses of the Pfizer-BioNTech or Oxford-AstraZeneca vaccination experienced moderate-to-severe adverse effects after receiving the Johnson & Johnson booster.

Furthermore, among younger people who got the Pfizer-BioNTech vaccine prime, the Oxford-AstraZeneca and Moderna booster doses caused a lot of negative effects. Both young and older persons who had been primed with the Oxford-AstraZeneca vaccination had negative effects after receiving the Moderna booster.

Are all COVID-19 vaccine boosters effective?

To examine the number of antibodies against the spike protein, the researchers took blood samples from the subjects 28 days after their booster dose. They also performed tests to determine the amounts of neutralizing antibodies and T cell response. The immunological response to the wild-type SARS-CoV-2, as well as the Alpha, Beta, and Delta variants, was assessed in these tests. All of the experimental booster vaccinations elicited greater antibody levels against the spike protein at 28 days than the control group among participants receiving two initial doses of either the Oxford-AstraZeneca or Pfizer-BioNTech vaccine. The Valneva vaccination was the only one that did not boost antibody levels in those who had already received two doses of the Pfizer-BioNTech vaccine.

Booster vaccinations produced equal increases in neutralizing antibodies against wild-type SARS-CoV-2 and variations of concern, according to the researchers.

The levels of neutralizing antibodies against the Delta variant of the coronavirus were somewhat lower than those against the wild-type coronavirus. In addition, the levels of neutralizing antibodies against the Delta variant and the wild-type coronavirus were linked.

Despite the advent of novel variations, the authors of the study conclude that employing vaccinations intended against the wild-type coronavirus is still the best option. After getting a booster with the Pfizer-BioNTech, Moderna, or Johnson & Johnson vaccination, those who got the Oxford-AstraZeneca or Pfizer-BioNTech vaccine prime demonstrated an increase in T cell response. Individuals who got all three doses of Oxford-AstraZeneca, on the other hand, did not exhibit a significant increase in T cell response as compared to the control group.

Furthermore, in people primed with two doses of either the Oxford-AstraZeneca or Pfizer-BioNTech vaccines, the Valneva vaccine — which employs inactivated the whole virus — did not boost T cell response. The most significant increases in immunological response were seen with the Moderna and Pfizer-BioNTech booster injections. The research, however, employed the full dose of the Moderna vaccine (100 micrograms of mRNA) rather than the CDC-approved half-dose. This is due to the fact that the trial was conducted in June before the vaccine was approved for use in booster injections.

In conclusion, our findings demonstrate that various vaccination boosters induce a wide range of immunological responses and inflammatory adverse effects. After considering the side effect profile, vaccine availability, and vulnerability to COVID-19, these findings will assist public health organizations and politicians to make recommendations for booster immunization programs.

Individuals who got a half-dose or full-dose of the Pfizer-BioNTech vaccine as a booster shot was included in the trial. Individuals primed with either the Pfizer-BioNTech or Oxford-AstraZeneca vaccine had equal increases in immune response from the half-dose and full-dose of the Pfizer-BioNTech vaccine booster injection. Additionally, persons who got the Pfizer-BioNTech vaccination half-dose as a booster had a somewhat better adverse effect profile. This might mean that a half dose of the Pfizer-BioNTech vaccine is enough to provide the targeted immunity increase.

What are COVID booster side effects?

Soreness, redness, or swelling at the injection site, weariness, headache, muscular pain, chills, fever, and nausea are all possible adverse effects of the COVID-19 vaccination in adults and children. Serious adverse effects are uncommon, although they can happen.

After receiving the COVID-19 vaccine, you may have transitory symptoms similar to those experienced after receiving a flu shot, such as a painful, swollen arm where the shot was administered. For a day or two, you may have a fever, as well as body pains, headaches, and exhaustion. Swollen lymph nodes and chills are other possible side effects. These signs do not indicate that you are ill. They show that your immune system is reacting to the vaccines and building up resistance to the coronavirus.

What are the methods?

COV-BOOST is a multicentre, randomized, double-blind, placebo-controlled phase 2 study of COVID-19 third-dose booster immunization. Participants had to be at least 70 days after receiving two doses of ChAd or 84 days after receiving two doses of BNT main COVID-19 vaccination, with no history of laboratory-confirmed SARS-CoV-2 infection. Three groupings of 18 locations were formed (A, B, and C). Participants were randomly allocated to an experimental vaccination or control within each site group (A, B, or C). NVX-CoV2373 (Novavax; hereafter known as the NVX), a half-dose of NVX, ChAd, or a quadrivalent meningococcal conjugate vaccination (MenACWY) control were given to Group A. (1:1:1:1). BNT, VLA2001 (Valneva; hereafter referred to as VLA), a half-dose of VLA, Ad26.COV2.S (Janssen; hereafter known as the Ad26), or MenACWY were given to Group B. (1:1:1:1:1). mRNA1273 (Moderna; hereafter known as the m1273), CVnCov (CureVac; hereafter referred to as CVn), a half dosage of BNT, or MenACWY were given to Group C. (1:1:1:1). The treatment allocation was kept a secret from the participants and the whole research team. Safety, reactogenicity, and immunology of anti-spike IgG assessed by ELISA were coprimary outcomes. The primary analysis for immunology was done on a modified intention-to-treat basis, with the intention-to-treat population being used to assess safety and reactogenicity. The evaluation of viral neutralization and cellular responses were secondary outcomes. ISRCTN number 73765130 has been assigned to this study.

The current situation in countries?

At least 126 nations have already given booster or supplementary immunization recommendations, and more than 120 have begun programmatic implementation. The bulk of these countries is high- or upper-middle-income countries. A booster immunization program has yet to be implemented in any low-income country. Older persons, health care professionals, and immunocompromised people are the most prevalent target demographics for booster doses (in immunocompromised individuals the booster dose is considered as an additional primary series vaccination dose by WHO). In the eligible adult population, the level of primary immunization coverage varies. The coverage rates for full primary immunization are below 30% in some of these nations that offer booster doses.

The big picture (global context)

To address the persistent and deep imbalance in global vaccine access, WHO Director-General Margaret Chan has proposed a halt on booster immunization for healthy individuals until the end of 2021. (2). While many nations are still far from attaining the aim of 40% coverage by the end of 2021, others have already immunized significantly more children and are launching substantial booster immunization programs. At the time of publication, around 20% of COVID-19 vaccine doses were being utilized for booster or extra dose immunization across the world.

Vaccine booster dosage policy choices should be supported by evidence of individual and public health benefits, as well as commitments to provide worldwide fairness in vaccine availability in order to reduce health consequences and transmission, as well as the risk of variations and pandemic prolonging. While the vaccination supply is increasing, it is not being distributed equally. Lower-income nations have had significantly less access to resources, and their supply is unreliable and irregular. Within nations, fairness considerations favor increasing primary vaccination series coverage in high-risk groups as the highest priority use of vaccine doses.

To conclude, we can say that all COVID-19 vaccine boosters are safe and effective.

Writer: Ziana Jesin Bhuiyan

Brac University

Department of Computer Science and Engineering (CSE)

Edited By: Al-Resalat

BA, MA  in English Language And Literature