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The Covid-19 vaccines and what we know so far

MONDAY saw the start of South Africa’s vaccine programme with the arrival of the first batch of vaccinations intended for frontline healthcare workers. There is lots of speculation and misinformation being spread about the vaccines themselves, so here’s a look at the facts.


How was it developed so quickly?

Several manufacturers having been racing against time to perfect a Covid-19 vaccine, resulting in one of the quickest vaccine developments in human history. This is not to say any corners were cut, in fact, the building blocks of the vaccine have been in place for years and scientists have essentially been planning for ‘disease X’ – which happened to be Covid-19 – for a while now. Information from previous coronaviruses – Sars and Mers – gave scientists a major head start plus, with the financial restrictions eradicated, vaccine manufacture was made that much easier. All necessary clinical trials have taken place which include:


· Phase one - The vaccine is tested in a small number of people to check it is safe.

· Phase two - Safety tests in more people, and to look for signs the vaccine is producing the required response.

· Phase three - The big trial, involving thousands of people, to prove it actually protects people.


Nothing was sped up, just the years of waiting in between each phase were eradicated.


What vaccine are there?

A number of companies have had success with vaccine trials, and have started distributing their product globally. There are actually many vaccines currently in development, but not all have been approved for use as yet. Here are three that have.


1. Moderna Therapeutics (Name: mRNA-1273)

Developed by a Massachusetts-based biotech company, in collaboration with the National Institutes of Health, the vaccine has an efficacy rate of 94.1%. Although Moderna stated on 25 January 2021 that it is effective against the new variants, further peer-reviewed studies would be needed to verify this. The vaccine requires two injections given 28 days apart, although the second dose can be given up to six weeks after the first dose, if needed.


2. University of Oxford / AstraZeneca (Name: ChAdOx1 nCoV-19)

Developed by Oxford University, in collaboration with the biopharmaceutical company AstraZeneca. It has an efficacy of 76% after the first dose, increased to 82% after the second dose, administered 12 weeks or more apart.


3. Pfizer-BioNTech (Name: BNT162b2)

Developed by the New York-based pharmaceutical company, Pfizer, in collaboration with German biotech company BioNTech. The vaccine has an efficacy rate of 95% and can be used by people age 16 and older. It requires two injections given 21 days apart. The second dose can be given up to six weeks after the first dose, if needed.


What are the types of Covid-19 vaccines?

We’ve looked at some of the approved vaccine options on the market, but each vaccine has a different structure. Here are the types of vaccines as well as how they work:


· Inactivated or weakened virus vaccines - These actually use a form of the virus that has been inactivated or weakened so it doesn’t cause Covid-19, but still the body will still generate an immune response to it.


· Protein-based vaccines – These use harmless fragments of proteins or protein shells that mimic the COVID-19 virus to safely generate an immune response.


· Viral vector vaccines – These use a genetically-engineered virus so that it can’t cause disease, but produces coronavirus proteins to safely generate an immune response. The University of Oxford /AstraZeneca is one such example.


· RNA and DNA vaccines – This is a cutting-edge approach that uses genetically-engineered RNA or DNA to generate a protein that safely prompts an immune response. Both the Pfizer-BioNTech and Moderna Therapeutics vaccines are in this format.


Will they provide long-term protection?

As mentioned, the window for the manufacture and distribution of the vaccines has been incredibly small because of the pandemic and desperate need worldwide, which is why it’s still too early to tell if the Covid-19 vaccines will produce long-term protection. While additional research is still needed, existing data regarding people recovering from Covid-19 and developing immunity is promising.


Will they protect against variants?

A big fear currently is the arrival of new Covid-19 variants and what impact existing vaccines will have on them. Early research suggests that both the Pfizer-BioNTech and Moderna Therapeutics vaccines, which are RNA and DNA vaccines, can protect against the variants identified in the United Kingdom and South Africa. However, manufacturers are looking at creating booster shots for enhanced protection.


What is Covax?

President Cyril Ramaphosa has mentioned ‘Covax’ a number of times in his addresses, but few understand what it actually means. Covax is a global alliance of governments (including South Africa’s), global health organisations, manufacturers, scientists, the private sector, civil society and philanthropy, to provide innovative and equitable access to COVID-19 vaccines. Basically, Covax aims to ensure that every person worldwide, no matter what status, has access to the Covid-19 vaccine.


Understandably many people are hesitant about being vaccinated, but if we all take ‘I’ll wait to see what happens’ approach, we’re not going to reach the required 67% immunity, which means living with Covid-19 forever. Vaccines have proved effective in eradicating life-threatening and debilitating diseases for decades, and this one should prove no different.


*Sources:

World Health Organization (www.who.int)

Mayo Clinic (www.mayoclinic.org)

National Institute for Communicable Diseases (www.nicd.ac.za)

National Geographic (www.nationalgeographic.com)

BBC News (www.bbc.com)



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