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Wits Vaccines & Infectious Diseases Analytics (VIDA) Research Unit

Oxford COVID-19 Vaccine Trial

Interim Study Results February 2021: Next steps for participants and FAQ

Thank you for taking part in the Oxford COVID-19 vaccine trial. You may have heard that the vaccine has now been rolled out in the UK, that vaccines have arrived in South Africa, and that the interim results of the trial have been released. This FAQ document is for trial participants and members of the public who may have questions relating to the study and vaccination in South Africa. Trial participants can contact their trial site with any queries that may not be answered here. Please note: this document does not include official information from the South African National Department of Health (DOH). Please follow official DOH channels for official information regarding vaccination rollout plans.

Questions about the Oxford Astra-Zeneca vaccine

The results show limited efficacy – what does this mean and should we still consider taking this vaccine?

Emerging data suggest that the Oxford-AstraZeneca vaccine may not protect against mild disease caused by the South African variant (B.1.351) of the virus in young adults, while it did provide good protection against the original variant in the country. In this study we did not assess whether the vaccine protected against severe disease including hospitalisation and death, but we are planning studies to assess this. The evidence from other viral vector vaccines is encouraging, indicating that similar vaccines do prevent severe disease caused by this variant. By continuing with clinic visits, and informing us if you have symptoms of COVID-19, you are providing ongoing data about how long the vaccine offers protection and whether it offers protection against new strains of the virus.

We are offering all vaccine recipients a third or booster dose of the vaccine, and would like to assess the antibody responses in some participants to this third dose.

Does the Oxford AstraZeneca vaccine protect against COVID-19?

The original strain is still circulating in South Africa and around the rest of the globe, and may, over the months and years to come, become the dominant strain. Being vaccinated with a vaccine that protects against the original strain is still important for travel as well as for potential resurgence of this strain. It is also important to protect vulnerable populations (such as the elderly and high-risk individuals, including health care workers) from COVID-19. While the efficacy of the Oxford AstraZeneca vaccine is limited in terms of protection against mild and moderate disease caused by the B.1.351 strain of the virus, there is a possibility that the vaccine may offer some degree of protection, especially from severe disease.

The Oxford Vaccine Trial team have confirmed that efforts are underway to develop a new generation of vaccines that will allow protection to be redirected to emerging variants as booster jabs, if further data suggests this is required.

The DOH and scientists are discussing all possible options for vaccine roll out. It is understood that various options are being discussed. Vaccination of healthcare workers with the J&J vaccine has begun as of 17 February 2021. Please refer to the Department of Health’s official channels for information on the government’s roll out plan for vaccines

Additional information for trial participants in South Africa

I am a participant in the Oxford vaccine trial. What happens now?

All participants will need to find out what they received in the study. You might have had two doses of the study vaccine, or one dose (if you were randomised to the vaccine arm but missed the second dose for any reason), or you might have been part of the control group, in which case you would have received one or two placebo injections containing sterile normal saline (0.9% NaCl).

Trial participants who received placebo injections during the study will be invited to return to their trial site to receive two doses, eight weeks apart, of the of ChAdOx1 nCoV-19 vaccine. Trial participants who received one (i.e. enrolled in vaccine arm, but missed dose two) or two doses of ChAdOx1 nCoV-19 vaccine as part of the trial will be offered a further dose of ChAdOx1 nCoV-19 vaccines from mid-March 2021.

Any trial participants who are health care workers and who are invited to receive the J&J vaccine as part of national roll out (from 17 February 2021) will be able to receive the J&J vaccine if they wish to.

As the study is a double-blinded, randomised, placebo-controlled trial, this means that very few people have access to information about whether participants received the vaccine candidate or a placebo injection, until a certain point in the study analysis. Even with the reporting of the recent results, the trial investigators are still blinded as to which arm of the trial you were randomised to. All investigators and trial participants usually remain blinded to treatment arm until such time that either an individual (for receipt of roll-out vaccines) or all the trial participants as a whole (end of trial) need to be unblinded. In this case, early unblinding of all trial participants will take place.

Participants who are healthcare workers:

  • If you have received an invitation for the J&J vaccine, please contact your trial site. The trial site will inform participants as to which treatment arm they were randomised to (i.e. whether you received the placebo or the ChAdOx1 nCoV19 vaccine)
  • Participants can choose to accept the DOH vaccine whether or not they have been unblinded. If you would like to be unblinded prior to receiving the vaccine, please contact the trial site who will be able to unblind you
  • Participants who are invited and accept a DOH vaccine are requested to inform their trial site and provide a copy of their vaccination card or record at the next visit.
  • All participants will be asked to remain on the trial for the full 12-months after the initial trial enrolment date for follow-up as detailed in the initially approved protocol, as approved by SAHPRA.

All other trial participants:

  • The trial site will contact and inform participants as to which treatment arm they were randomised to (i.e. whether you received the placebo or the ChAdOx1 nCoV19 vaccine).
  • Trial participants will be invited to return to their site to receive two doses, eight weeks apart (placebo recipients) or one dose (ChAdOx1 nCoV-19 recipients) of ChAdOx1 nCoV-19 vaccines from mid- March 2021.
  • All participants will be asked to remain on the trial for the full 12-months after initial trial enrolment date for follow-up as planned. You can also contact your site by telephone if you have any questions about this information.
Do we still need to take part in the study?

The studies will carry on collecting data, even after the first vaccines are approved and rolled out. This essential to gather information about the long term safety of the vaccine and also to see how long immune responses to vaccine last for. If you choose to accept an approved vaccine as part of the DOH national roll out, we ask you to continue participating in the Oxford study, including attending study visits as planned. Your continued participation is valuable and appreciated.

General questions

Isn’t any vaccine better than no vaccine in the fight against COVID-19?

When a vaccinated person is exposed to natural infection after being vaccinated, their immune system, which has gone through a ‘vaccine-induced training session’ to fight the bug, will identify the bug (pathogen) immediately, and start to fight it before it has a chance to cause severe symptoms.

In contrast, when someone who has not been vaccinated against a certain disease is first exposed to the bug, the body needs to identify the bug/pathogen and try to work out how to fight it before it can actually get rid of it. This delay between exposure to a disease and the body learning how to fight it, may be long enough to allow for extensive ‘invasion’ of the body by the bug. During this time, the body can become very ill.

The COVID-19 vaccines developed against the ‘original’ SARS-CoV-2 virus strain could potentially protect against disease caused by different strains, because much of the spike protein in ‘original’ and ‘variant’ strains is the same in both.

Vaccination may reduce the speed of the spread of SARS-CoV-2, which helps to reduce the chance of virus mutations forming. Mutations are ‘spelling mistakes’ or ‘altered spelling’ of the virus’s genetic code, which could either be accidental, or intentional, such as when the virus realises it may be under attack and tries to hide from the immune system.

Oxford and other vaccine manufacturers are already working on developing vaccines against identified variants and there are some vaccines which have encouraging efficacy data against the B.1.351 variant.

I don’t understand the comparisons with other vaccine platforms and trials in the media. Please help?

Vaccines are made using different ‘platforms’ and technologies. The aim of all vaccines is to ‘show’ the body a part (or all) of the SARS-CoV-2 virus, and allow the body to recognise that the virus/fragment of the virus is something foreign and learn how to fight the virus.

The ‘platforms’ include using parts (or clippings) of the genetic code of the spike protein (instructions to make the spike protein: mRNA, DNA), inserting these ‘clippings’ into a carrier molecule (viral vector), the whole, killed virus, or little pieces of the spike protein.

Results that are being reported are for different phases of clinical trials (phase 1, 2 or 3), and for different severity of disease (asymptomatic carrier, mild, moderate, severe, hospitalisation, death).

Phase 1 trials are early phase trials in humans, looking specifically at the safety of the vaccine in a small group of people (usually <10-<100 people).

Phase 2 trials follow on phase 1 trials and specifically look at the immune response that the body mounts against the vaccine (immunogenicity, usually 100- <1000 people).

Phase 3 trials follow up thousands of people who receive a vaccine or placebo, and specifically look at how effective the vaccine is at reducing disease caused by the pathogen/bug.

The South African trial is a combined phase 1 and 2 trial, with an added efficacy objective. Some trials, including the South African trial, are designed to be able to look at multiple objectives.

What vaccines will be available in South Africa, and when will I be offered a vaccine?

In addition to the doses of the Oxford AstraZeneca vaccine that have already arrived in South Africa, there are many vaccine candidates that have been approved for use after extensive clinical trials and regulatory review around the world. It is understood that the Department of Health is in negotiations with various vaccine production, distribution and pharmaceutical companies. Please continue to follow the official channels for updates on the government’s roll out plan.

The government is likely to prioritise which groups should receive a vaccine as part of the roll out. For some people this could be months away and others sooner.

What if I am invited to have a vaccine?

First of all, you should decide whether you wish to accept the vaccine that is being offered to you; this is for you to decide on the basis of information provided to you by the Department of Health and your health care professionals.

What is the difference between B.1.351 and 501Y.V2?

B.1.351 and 501Y.V2 are both official scientific terms for the current coronavirus strain circulating predominantly in SA.

Will we need to have annual COVID-19 vaccines, like we do Flu injections?

It is important that extensive research is conducted in different parts of the world to improve our understanding of SARS-CoV-2 and how to treat COVID-19 and protect against mild, moderate and severe disease. It is possible that annual vaccination against SARS-CoV-2 virus may be needed.