The next few days will be crucial in determining how South Africa continues with its Covid-19 vaccination roll-out.
The Food and Drug Administration and the Centers for Disease Control and Prevention in America suspended the use of the Johnson & Johnson vaccine “out of an abundance of caution” following six cases of women developing a rare condition causing blood clots in the brain, coupled with low platelets. The condition cannot be treated by normal blood thinners.
On Tuesday night, Health Minister Dr Zweli Mkhize announced that South Africa will also suspend use of the Johnson & Johnson vaccine, “hopefully only for a few days”, while clarity was obtained about a possible link between the vaccine and the six cases. All six women received the J&J vaccine.
The Johnson & Johnson vaccine, along with the Pfizer vaccine, will be rolled out in South Africa.
What did Sahpra say?
The SA Health Products Regulatory Authority (Sahpra) said in a statement on Wednesday that, together with its scientific expert committees, it recently reviewed the data from the Sisonke Phase 3b implementation study.
“This study involves the administration of the Covid-19 vaccine Janssen, which is also referred to as the Johnson & Johnson (J&J) vaccine. Based on these data, no major safety concerns have been identified.
“No causal relationship between vaccination and the development of blood clots is evident at this stage. However, following the decision by the United States Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) to pause the use of the J&J vaccine in that country, Sahpra met with the Sisonke study team and the manufacturer (Janssen Pharmaceutical) on 13 April 2021.
“Sahpra was provided with updated data on the Sisonke study. Further data are being obtained from the manufacturer and the FDA. Sahpra has requested a pause in the implementation of the Sisonke study to enable it to review the relevant data and further updates will be communicated in due course. It is envisaged that this process will take a few days.”
What about the health workers who received the vaccine?
The SA Medical Research Council, conducting the implementation trial that allowed health workers early access to the vaccine, said they have seen none of these rare blood clotting side effects in participants of the Sisonke Phase 3b study.
“We have nonetheless taken the decision to temporarily pause the Sisonke Phase 3b study until further information is available.”
The trial investigators said in a statement that 2.2% of healthcare workers who received the vaccine as part of the Sisonke study reported side effects or an adverse health event following vaccination.
“Only 134 people were referred for further evaluation at an emergency room or hospital. Most of these events have been minor, local or systemic reactions. One person experienced a severe allergic reaction that met the international diagnostic criteria for anaphylaxis, but has since made a swift and complete recovery.”
According to the statement, investigators have seen some adverse events involving blood clots during the study.
“We have noted some thromboembolic events (clotting events where the clot breaks off and travels to another part of the body to block a blood vessel), but none of those are similar to the serious condition identified in six recipients of the vaccine in the United States that involved a blood clot in the brain, coupled with a low platelet count.”
The statement also said that events involving blood clots have been reported on rare occasions following the administration of several Covid-19 vaccines.
“It is important to note that thromboembolic events are a common complication of Covid-19 infection; are associated with other commonly used medications including contraception, and with comorbidities such as obesity, diabetes and cardiovascular disease, as well as smoking.”
Commenting on the decision to suspend the use of the vaccine for a few days while clarity is obtained, the investigators said: “We understand that this may cause alarm among people who have already received the vaccine, and anxiety about Covid-19 vaccines in general. We wish to reassure health workers and the public that safety is our number one priority, and that this has guided our decision to pause the study temporarily.
“We note that temporary pauses in Covid-19 vaccine rollouts are not uncommon; have already occurred for other Covid-19 vaccines, and that they can generally be reversed once all safety data has been carefully scrutinised.
“Covid-19 continues to pose a great threat to the lives and livelihoods of our people, and vaccines provide one of the most effective solutions as we attempt to mitigate an end to the pandemic.”
What if you received the vaccine under the Sisonke protocol?
This is the advice provided by the Medical Research Council for health workers who have already received the vaccine.
“Cases of the rare clotting syndrome have occurred within the first three weeks of vaccination. If you received your vaccine more than three weeks ago and have no symptoms, you are not at increased risk of a thromboembolic event related to vaccines.
“If you have recently been vaccinated, and develop any of the following symptoms, we advise that you seek care urgently, advise your doctor that you have recently been vaccinated and ask them to contact the Sisonke desk on 0800 014 956.
“Symptoms that should prompt you to seek care are: breathlessness; pain in the chest or stomach; swelling or coldness in a leg, severe headache or blurred vision after vaccination; persistent bleeding; multiple small bruises, reddish or purplish spots, or blood blisters under the skin.
“Doctors managing these patients are advised to make immediate contact with the Sisonke desk and avoid heparin until a diagnosis has been established.”
What about other vaccines?
The FDA has not issued similar warnings for the Moderna and Pfizer vaccines that are used in the United States.
In a statement on Wednesday, the manufacturers of the Moderna vaccine stressed that these rare blood clots are not a side effect of their vaccine.
Earlier in March, the Medicines and Healthcare Products Regulatory Agency (MHRA) and European Medicines Agency reaffirmed that the benefits of the AstraZeneca vaccine “continue to far outweigh the risks”.
The AstraZeneca and Johnson & Johnson vaccines use similar technology.
This followed a review of similar cases where a small number of people – out of 11 million – developed blood clots and low platelets in the United Kingdom after receiving the vaccine.
A review by the UK’s MHRA of five cases of the same rare blood clot disorder is ongoing and a causal association with the vaccine has not been established. The review found the risk was extremely low – around four in a million who are vaccinated.
The MHRA’s review concluded that the “evidence of a link with Covid-19 vaccine AstraZeneca is stronger but more work is still needed”.
What does Johnson & Johnson say?
“We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our Covid-19 vaccine.
“The United States Centers for Disease Control and Food and Drug Administration are reviewing data involving six reported US cases out of more than 6.8 million doses administered. Out of an abundance of caution, the CDC and FDA have recommended a pause in the use of our vaccine.
“In addition, we have been reviewing these cases with European health authorities. We have made the decision to proactively delay the roll-out of our vaccine in Europe and pause vaccinations in all Janssen Covid-19 vaccine clinical trials while we update guidance for investigators and participants,” the statement reads. DM/MC
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