Since the onset of the novel coronavirus in late 2019 and the subsequent spread of it globally, the world has been on a frantic search for a vaccine. If lucky, a cure for the virus. Notable progress has been made since, with 5 vaccines approved by the World Health Organization (WHO). These are
- The Oxford AstraZeneca COVID-19 vaccine
- Pfizer BioNTech COVID-19 vaccine
- The Moderna COVID-19 (mRNA-1273) vaccine
- The Johnson & Johnson COVID-19 vaccine
- The sinopharm COVID-19 vaccine
Viruses, like the SARS-Cov-2, the virus that causes COVID-19, are constantly changing and evolving. This change is sometimes caused by errors that occur when the viruses copy their genetic material. Some errors have no effect, while some might even make the virus less viable. Some make the virus benign, while others make it more infectious.
How the vaccines work
Highlighted below are 4 of the widely used vaccines right now, and how they are administered.
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PFIZER-BIONTECH
On December 11, 2020, this became the first COVID-19 vaccine to receive approval after the company reported positive clinical trial data, which included news that the vaccine was up to 95% effective at preventing symptomatic diseases. However, the Pfizer-BioNTech vaccine has had strict requirements involving how the vaccine is stored. For instance, it has required shipping in ultra-cold temperature-controlled units (-94 degrees Fahrenheit). In mid-February, the company submitted new data to the FDA demonstrating the stability of the vaccine at temperatures more commonly found in pharmaceutical refrigerators and freezers. Approval would make the vaccine easier to distribute.
Recommended for: Anyone 12 or older.
Dosage: Two shots, 21 days apart
Common side effects: Chills, headache, pain, tiredness, and/or redness and swelling at the injection site, all of which generally resolve within a day or two of rest, hydration, and medications like acetaminophen.
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MODERNA
Moderna’s vaccine was the second one authorized for emergency use, about a week after the Pfizer vaccine. Moderna is also an mRNA vaccine, using the same technology as the Pfizer-BioNTech one and with a similarly high efficacy at preventing symptomatic disease. There are two key differences: The Moderna vaccine can be shipped and kept in long-term storage in standard freezer temperatures, and stored for up to 30 days using normal refrigeration, making it easier to distribute and store. Also, the Moderna vaccine was slightly less effective in clinical trials—about 86%—in people who are 65 and older.
Recommended for: Adults 18 and older.
Dosage: Two shots, 28 days apart
Common side effects: Similar to the Pfizer vaccine, side effects can include chills, headache, pain, tiredness, and/or redness and swelling at the injection site, all of which generally resolve within a day or two.
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JOHNSON & JOHNSON
In comparison to the Pfizer and Moderna vaccines, this one is easier to store (in refrigerator temperature), and requires only a single shot, which has made it easier to distribute and administer. An analysis released by the FDA in late February showed that the vaccine may reduce the spread of the virus by vaccinated people.
Recommended for: Adults 18 and older.
Dosage: Single shot. In November, Johnson & Johnson announced it would launch a second Phase 3 clinical trial to study using two doses, two months apart, to see if that regimen will provide better protection.
Common side effects: Fatigue, fever headache, injection site pain, or myalgia (pain in a muscle or group of muscles), all of which generally resolve within a day or two. It has had noticeably milder side effects than the Pfizer and Moderna vaccines, according to reports.
How well it works: 72% overall efficacy.
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OXFORD-ASTRAZENECA
This vaccine, which is currently being distributed in Africa, is distinguished from some of its competitors by its lower cost. It is cheaper to make per dose, and it can be stored, transported, and handled in normal refrigeration for at least six months. Some countries temporarily suspended use of this vaccine in March after a small number of recipients developed blood clots. However, regulators stressed that the benefits of the vaccine still outweigh the risks.
Recommended for: Adults 18 and older
Dosage: Two doses, four to 12 weeks apart
Common side effects: Tenderness, pain, warmth, redness, itching, swelling or bruising at the injection site, all of which generally resolve within a day or two.
The COVID-19 virus has evolved over time to more lethal variants. Currently, there are 4 COVID-19 variants namely
- B117 – First identified in the UK
- B1351 – First identified in South Africa
- P1 – First identified in Brazil
- B16172 – First identified in India
When a virus variant is spotted, it is usually classified as a variant of interest, concern or high interest. Virus variants are classified according to evidence of increased transmission, severity and significant reduction in antibody response or reduced effectiveness to vaccines or treatments.
There is evidence that all the COVID-19 variants discovered have increased transmissibility. A recent study has shown that the Pfizer BioNTech vaccine is 90% effective against the UK variant and 75% effective against the South African variant. The AstraZeneca vaccine, which is the most used vaccine globally, showed a 75% effectiveness against the UK variant.
Further research has shown that both the Pfizer and AstraZeneca vaccines are highly effective against the Indian variant, which has claimed many lives. Pfizer reached 88% effectiveness, while AstraZeneca achieved 60%.
In Kenya, 954,515 people have so far been vaccinated with the first shot of the AstraZeneca vaccine since vaccination commenced in March, 2021. With reduced supply from COVAX, Kenya currently has a challenge vaccinating its entire population. According to the Ministry of Health, Kenyans should expect the second dose of the vaccine starting June 2021.
While the effectiveness of the vaccines is promising, the WHO warns that there is a chance of more variants emerging. Everyone qualified for the vaccines has been encouraged to get the first and second shots of the vaccines as soon as they are available to them.
Getting vaccinated is the first step in curbing the COVID-19 menace. Universal vaccination and subsequent booster shots will go a long way in the war against COVID-19. In the meantime, let us all endeavor to wash our hands regularly with soap and water, sanitize, wear masks while in public places and maintain social distancing.
