Promising new data on Oxford Vaccine

Data published today has given promising results on the Oxford vaccine

The Lancet published the first results from the Oxford vaccine study today. The results look promising.

Safety

• 1077 people mean age 35 were studied, of whom 543 received the new active vaccine. A small number (10 subjects) received a booster dose
• There were large numbers of mild reactions including headache, fatigue and other flu like sympotms, all of which lasted only a couple of days
• Paracetamol taken before vaccination reduced some of these side effects
• There were no serious reactions
• In the 10 subjects who received a booster vaccine, the side effects were less severe with this second dose
• The dose of virus in the vaccine was quite high which was considered necessary to produce rapid immunity. (I am not sure if a lower dose had been used it would have produced less severe side effects with the same benefit in terms of immunity-see below)

Effectiveness

• This report focused on safety, but a small proportion of the participants had various laboratory tests to assess whether the vaccine would produce the desired immune response
• There was a very good immune response in terms of the level of antibodies, which after one dose had peaked at 28 days .
• The antibodies were also shown in the laboratory to be ‘neutralising’ ie capable of preventing the virus from causing disease. This was 100% the case in the small number that had a booster dose
• For people with pre-existing evidence of antibodies (from natural infection), their immune response was enhanced by the vaccine

Comment

• The authors have been rightly cautious about these early results and the issues I mentioned in my previous blog about vaccine remain
• It is interesting to see the results from giving a booster (although very small numbers). This suggests that if and when this vaccine is introduced, a booster may be part of the vaccination routine
• It is good news that the immune response produced by the vaccine was ‘neutralising’ – this one of the outcomes the study needed to confirm
• The results are from healthy young, predominantly white, volunteers. The level of side effects was acceptable in that group but needs to be studied of course in older people (which is happening).
• Similarly we await how suucessful the vaccine will be in terms of achieving an immune response in the elderly