J&J, Pfizer and Sinovac vaccines: Here’s what you need to know
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DURBAN - With just over three million people receiving their Covid-19 vaccines, South Africa is set to begin the roll-out of the Sinovac-CoronaVac vaccine. Manufactured in China, the Sinovac vaccine is the third vaccine to be administered in the country. The inoculation programmes with the other two vaccines, Johnson & Johnson and Pfizer, have already kicked off.
All three vaccines have been approved by the South African Health Products Regulatory Authority (Sahpra).
But with the new Delta variant, just how effective are these vaccines and what are their side effects? Let's find out.
Johnson & Johnson vaccine
Studies have found that the J&J vaccine lasts at least eight months against the Delta variant. J&J head of research and development, Dr Mathai Mammen, said current data for the eight months studied so far show that the single-shot J&J Covid-19 vaccine generates a strong neutralising antibody response that does not wane.
“We observe an improvement over time. In addition, we observe a persistent and particularly robust, durable cellular immune response. With each new dataset, we build on our solid foundation of evidence that our single-shot Covid-19 vaccine plays a critical role in ending the pandemic, which continues to evolve and pose new challenges to global health,” he said.
A single dose of the J&J Covid-19 vaccine generated neutralising antibodies against a range of Sars-CoV-2 variants of concern, which increased over time including against the increasingly prevalent and more transmissible Delta (B.1.617.2) variant, the partially neutralisation-resistant Beta (B.1.351), the Gamma (P.1) variants and others.
As for side effects, there have been reports of the injection site being red or swollen as well as headaches, fatigue, muscle pains and fever. There is a very remote chance of people complaining of severe allergic reactions - difficulty in breathing, a swelling of face and throat, an irregularly fast heartbeat, a rash, dizziness or weakness. There have also been reports of people experiencing blood clots.
Pfizer-BioNTech COVID-19 vaccine
The two-dose Pfizer-BioNTech Covid-19 vaccine has a 70% efficacy rate against the Delta variant. According to a study conducted in Israel, the new finding is compared to the 95% rate of effectiveness of the vaccine against earlier virus strains. However, recent reports have shown a drop in efficacy in Israel.
Bloomberg reported that the vaccine’s efficacy against mild forms of Covid-19 appeared to wane after a few weeks as the Delta variant took hold in Israel, although it continued to protect against severe illness.
Possible side effects from the Pfizer vaccine include; pain and swelling around the injection site as well as fatigue, chills, fever, nausea and headaches. According to the Centre for Disease Control and Prevention, these are normal and last only a few days.
This two-dose vaccine is recommended for individuals aged 18 years and above.
The World Health Organization reported that a large phase 3 trial in Brazil showed that two doses, administered at an interval of 14 days, had an efficacy of 51% against symptomatic Sars-CoV-2 infection, 100% against severe Covid-19, and 100% against hospitalisation starting 14 days after receiving the second dose.
CoronaVac is an inactivated vaccine. It uses a dead version of the Sars-CoV-2 virus so that it cannot replicate, but it keeps the surface spike protein intact to trigger the body’s immune system to create antibodies for protection against the live virus, if it were to invade.
Side effects include fatigue, diarrhoea and muscle pain, which last for about two days.
Thus far, Sahpra has approved the AstraZeneca, Pfizer, Sinovac and the J&J vaccines. Sahpra has also received the Sputnik V vaccine, manufactured by the Gamaleya Research Institute.
Sahpra chief executive Dr Boitumelo Semete said the Sputnik V application is a rolling review.
Vaccine registration is now open for those aged 50 and over.