Publications
Partners
- The Pfizer Covid-19 vaccine has been approved as a two-dose schedule given 21 days apart
- However, emerging evidence shows a longer gap between the two doses may be beneficial
- SA will implement a 42-day interval between the two doses to offer shots to as many people as possible
The vaccine developed by Pfizer-BioNTech requires two doses to be effective against Covid-19.
Health agencies, such as the US Centers For Disease Control and Prevention (CDC), recommend that the two-dose vaccine be administered 21 days apart but also state that “up to 42 days between doses is permissible when a delay is unavoidable”.
On Wednesday, Dr Sandile Buthelezi, Director General of South Africa’s National Department of Health said in a statement that, based on emerging evidence, the country’s vaccination programme will administer the two Pfizer vaccines 42 days (six weeks) apart.
Phase 2 of the programme was launched on Monday and is open to South Africans aged 60 and older.
According to the statement, the Ministerial Advisory Committee on Covid-19 Vaccines (VMAC) has considered the currently available vaccines after looking at data on their safety, efficacy, logistic implications, and registration with the South African Health Products Authority (Sahpra), among other factors. Based on this, the Pfizer vaccine has been procured as one of the vaccines to be used in the country’s rollout programme.
“There is currently emerging evidence to support a 42-day interval between the first and second doses. The VMAC has reviewed the available evidence in this regard and advised that, in the event of limited vaccine supply, the dosing interval should be extended to 42 days,” said Buthelezi.
Buthelezi added that the recommendation of 42 days between shots may change if further data become available. The scheduling on the Electronic Vaccination Data System (EVDS) will be programmed accordingly.
Mkhize: 'We want our people to be very patient'
This comes after health minister Zweli Mkhize said on Tuesday that the public shouldn't be concerned about a long gap between receiving the first and second shots, News24 reported.
"Between now and the end of June, we should have received close to six million vaccines. We are trying to get more than that, but because of some of the delays, we are getting our delivery scheduled for later in the year,” Mkhize said.
He added: "We want our people to be very patient because we might want to delay the second dose by up to three months."
What some of the data show
Pfizer’s clinical trials did not compare different dose spacings or compare one with two doses, but a new preprint study by the University of Birmingham in the UK recently found that delaying the second dose of the Pfizer vaccine to 12 weeks significantly increased the antibody responses in older people.
According to the findings, the antibody response in people aged over 80 was three-and-a-half times greater in those who received the second dose after 12 weeks compared to those who got it at the recommended three-week interval.
Another study, published in PLOS One, found that a nine-week delayed second dose of the Pfizer vaccine resulted in reduced Covid-related hospitalisations and death, compared to patients who had followed the three-week recommended interval between doses.
Other countries delaying doses
Several other countries have extended the dosing intervals for the Pfizer and Moderna vaccines. Earlier this year, the UK’s chief medical officers announced that the Oxford and Pfizer vaccines would be given 12 weeks apart, and that getting more people vaccinated with the first jab "is far more preferable", the BBC reported.
Denmark also approved a delay of up to six weeks between the first and second shots of the vaccine, according to a Reuters report. France followed this route in April in an attempt to ramp up their rollout.
*For more Covid-19 research, science and news, click here. You can also sign up for our Daily Dose newsletter here.
READ | Got the Covid-19 vaccine? Here are five things you should do if you have an allergic reaction
READ | Struggling to convince someone who's vaccine-hesitant to get Covid-19 jab? Try this approach
READ | Mixing Pfizer and AstraZeneca Covid vaccines increases mild side effects, early results show
