Mixing Covid-19 vaccine doses safe but increases side effects: Study

Mixing the doses of different types of two-dose coronavirus vaccines has been found to be safe but increased the frequency of mild to moderate symptoms, a new UK study has found.

The COM-COV study, led by the University of Oxford, has been investigating the immune responses of volunteers given a dose of the Oxford/AstraZeneca vaccine followed by the Pfizer/BioNTech jab, and vice versa, since February.

In its report for the medical journal Lancet on Wednesday, the research team said adverse reactions from this mix and match approach were short-lived and there were no other safety concerns.

The findings at this stage are limited to “reactogenicity” findings, or how people feel after the vaccine, and not the immunogenicity findings, that is how well the mixed dosing worked at inducing an immune response, work on which remains ongoing.

“The results from this study suggest mixed dose schedules could result in an increase in work absences the day after immunisation, and this is important to consider when planning immunisation of health care workers,” said Matthew Snape, associate professor in paediatrics and vaccinology at the University of Oxford.

"Importantly, there are no safety concerns or signals, and this does not tell us if the immune response will be affected. We hope to report these data in the coming months,” he said.

The mild side effects included symptoms like chills, fatigue, headaches and feeling feverish, and were short-lived. The research suggests that as the study data was recorded in participants aged 50 and above, there is a possibility such reactions may be more prevalent in younger age groups.

One in 10 of over 800 volunteers given two AstraZeneca jabs four weeks apart reported feverishness – but if they received one AstraZeneca jab and one Pfizer, in any order, the proportion rose to about 34 per cent.

Last month, the study was expanded to add another 1,050 volunteers to test combinations of the Moderna and Novavax Covid vaccines, alongside the Pfizer and AstraZeneca, which is being produced in India as Covishield.

China backs talks on intellectual property waiver for Covid jabs

China’s Commerce Ministry spokesman Gao Feng said on Thursday that Beijing supports a proposal by the World Trade Organization for an intellectual property protection waiver on Covid-19 vaccines to enter the consultation stage. British and European Union officials have been sceptical about the usefulness of a US proposal to waive patent protections for Covid-19 vaccines, while saying they are prepared to discuss it.

Drugmakers and some other governments opposed the idea, saying it would not solve global inoculation shortages.

“China supports the WTO’s proposal on IP exemptions for anti-epidemic materials such as the Covid vaccine to enter the text consultation stage," Gao said at a regular news conference in Beijing.

“China will work with all parties to actively participate in consultations and jointly promote a balanced and effective solution,” he said.  Reuters

Top scientists question need for booster jabs

In interviews with Reuters, more than a dozen infectious disease and vaccine experts said there is growing evidence that a first round of vaccinations may offer enduring protection against Covid and most of its variants discovered. Some expressed concern that expectations around boosters are being set by pharmaceutical executives rather than health specialists.  Reuters