From Wednesday, 23 February, South Africans will have more options to choose from for their booster shots. It becomes possible this week to access a different vaccine from the one initially received.

These are some of the changes to the coronavirus vaccination rules as set out by the National Department of Health:

• The interval between two doses of the Pfizer vaccine will be reduced from 42 days to 21 days.
• A booster shot is now available within three months after the second dose of the Pfizer vaccine.
• People who received the single-shot Johnson & Johnson vaccine will be able to access one shot of a Pfizer vaccine as a booster, 60 days after they were first vaccinated.
• People who received the Pfizer vaccine will be allowed to access a Johnson & Johnson booster shot three months after their second dose.

In a circular published by Dr Sandile Buthelezi, director-general of the national Department of Health, “homologous” boosters (a booster from the same manufacturer as the primary vaccine) were preferred, but those who wish to do so can ask for a booster from another manufacturer.

Buthelezi said in the circular that the Electronic Vaccination Data System (EVDS) was being updated to reflect these changes. 

On 25 January, pharmaceutical company Pfizer announced the initiation of a clinical study to evaluate an Omicron-based vaccine candidate in healthy adults.

This came a month after the company admitted that their vaccine proved ineffective in preventing infections with Omicron and that a booster would be needed.

“While current research and real-world data show that boosters continue to provide a high level of protection against severe disease and hospitalisation with Omicron, we recognise the need to be prepared in the event that this protection wanes over time and to potentially help address Omicron and new variants in the future,” Kathrin Jansen, head of vaccine research and development at Pfizer, said in a statement.

“Staying vigilant against the virus requires us to identify new approaches for people to maintain a high level of protection, and we believe developing and investigating variant-based vaccines, like this one, are essential in our efforts towards this goal.

“Vaccines continue to offer strong protection against severe disease caused by Omicron. Yet, emerging data indicate vaccine-induced protection against infection, and mild to moderate disease wanes more rapidly than was observed with prior strains,” said Professor Uğur Şahin, CEO and co-founder of BioNTech, the company that partnered with Pfizer in the development of the vaccine.

“This study is part of our science-based approach to develop a variant-based vaccine that achieves a similar level of protection against Omicron as it did with earlier variants but with longer duration of protection.”

Preliminary results from the Sisonke trial of health workers, published in December, showed that a homologous booster (the same as the original vaccine) was 85% effective against Covid-related hospitalisation at a time when the Omicron variant was dominant in South Africa. Health workers received the Johnson & Johnson vaccine.

Another analysis of vaccine recipients’ immune responses at the Beth Israel Deaconess Medical Center showed that a heterologous booster (a different vaccine) generated a 41-fold increase in antibodies in the body, while a homologous booster elicited a 17-fold increase.

Meanwhile, Buthelezi also signed off on new isolation and quarantine protocols for the country late last week.

These include that people who tested positive for Covid – but do not have any symptoms – do not need to isolate. For five days from the date of testing, however, they are advised to wear a mask whenever interacting with people, avoid social gatherings and avoid contact with people who are at high risk.

The exceptions to this rule are patients who have tested positive but are asymptomatic and need admission to hospital for other reasons, as well as residents of care homes, like old age homes, who will be required to isolate in separate rooms for five days.

Health workers who test positive for the virus but are asymptomatic will be required to isolate for five days.

People who develop mild Covid, for which they do not need to be hospitalised and if they are not diagnosed with Covid-19 pneumonia, must isolate themselves for seven days from the start of symptoms.

People who contract severe Covid are required to isolate themselves for seven days after they no longer need supplemental oxygen.

Quarantine is stopped in most cases. Quarantining applies to people who test negative for the virus but were exposed to someone who was infected.

All contact tracing will stop, except in congregate settings like care homes and healthcare facilities. DM/MC

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