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Regulators Cross Fine Line in Evaluating AstraZeneca Vaccine – POLITICO

The problems never end with the Oxford / AstraZeneca vaccine.

After all the struggles over contracts and deliveries, the final challenge is for European regulators: recommending that national governments not administer the vaccine to young people, citing a rare but sometimes fatal form of blood clotting.

Several countries have already taken this step and on Tuesday, the head of the vaccine strategy of the European Medicines Agency spoke out on the situation.

“Clearly there is a link,” Marco Cavaleri told Italian newspaper il Messaggero when asked if the vaccine caused the low platelet count and blood clots found in some people who received the vaccine.

“What is causing this reaction, however, we don’t know yet,” Cavaleri said.

The EMA is expected to make a more official vaccine safety announcement on Wednesday or Thursday.

Cavaleri’s comments were a notable change from the EU regulator, which has spent the past two months insisting that there was no reason for EU countries to restrict or stop using the vaccine – first in February when concerns were expressed about the lack of data to use the vaccine in the elderly, and again in March because of early concerns about serious blood disorders.

The UK, which has shown an enviable vaccination rate thanks in part to doses of the vaccine, is also seeing increasing reports of rare but serious blood clots. Channel 4 reported on Monday that UK regulators are considering restricting the vaccine in young people, a potentially huge blow to the UK vaccination campaign, although the agency said it had made no changes to its advice … “for now.”

Regulators are reluctant to limit the use of the vaccine because, as Cavaleri pointed out, while there may very well be a link between blood clots and the vaccine, its benefits always outweigh its risks.

A very small number of people could have serious side effects – but the vaccine clearly prevents thousands of people from dying with COVID-19.

“In short, if you are currently offered a dose of the Oxford-AstraZeneca vaccine, your chances of staying alive and well will increase if you take the vaccine and decrease if you don’t,” Adam Finn, professor of pediatrics at the University of Bristol, wrote in a press release.

Cavaleri has given no indication whether the EMA will change course in the short term and advises against giving the vaccine to young people. Instead, the decision could be up to each country, weighing how much caution they wish to exercise.

“Above all, let’s not forget that the weight of COVID is different depending on the country: in Italy, 500 people still die per day; in Norway, almost none, ”Cavaleri said. “These factors justify different approaches.”

Given that Europe is the most vaccine-skeptical continent in the world, and how cautious countries have been so far, it is likely that EU countries will continue to set targets. age restrictions for the Anglo-Swedish vaccine, especially if blood clotting reports continue to accumulate. up.

As Europe awaits news from the EMA this week, here’s a look at the main issues regulators face:

Is there a serious problem with the AZ vaccine?

European countries have distributed more than 40 million doses of the Oxford / AstraZeneca vaccine. The vast majority of people have not had any problems – the most common side effects are simply pain where the needle entered and basic flu-like symptoms, similar to other vaccines .

Still, there have been a very small – but increasing – number of people who have developed rare blood clotting problems around 14 days after receiving the vaccine.

Last week, Emer Cooke, executive director of the EMA, said there had been 62 reported cases of blood clots in the brain internationally – including 44 in the European Economic Area – as of March 22. Cerebral venous sinus thrombosis (CVST) and eight cases of thrombosis related to low platelet count as of March 24 (both of these conditions involve blood clots). Germany reported 31 cases of blood clots in the brain on March 30.

Some regulators have reported cases of thrombocytopenia, which is when a person has an abnormally low level of blood platelets (which stop bleeding by clumping and forming plugs in damaged blood vessels). Thrombosis is a general term for a blood clot anywhere in the body, while cerebral venous sinus thrombosis (CVST) – sometimes called cerebral sinus venous thrombosis (CSVT) – occurs when a clot occurs in the venous sinuses of the brain, preventing the blood from flowing from the brain and causing a stroke.

These events tend to be more common in younger women. Most of the reports sent to European regulators involved women between the ages of 22 and 50, although some women are between 50 and 60, Cavaleri said. About 20 percent of the cases were men in their 40s.

How unusual is that?

Peter English, former chairman of the British Medical Association’s public health medicine committee, told reporters UK reports of CVST events stand at around 1.2 cases out of a million doses used.

The EMA said that on average there are between 2 and 5 cases of CVST in 1 million people. However, the incidence rate varies depending on the study. Given that the rate quoted by the UK regulator – the Medicines and Healthcare products Regulatory Agency (MHRA) – last week isn’t that far off the typical number of cases a country would see in a year anyway. Given, English wrote that cases related to the Oxford / AstraZeneca vaccine are “far from strong evidence of causation.”

The Englishman also cautioned against reporting bias. Now that doctors are aware of the problem and are actively researching it, they may find more. “Remember that this is a ‘difficult diagnosis’, which suggests that it can often be missed, and if you look for it more carefully in one group than in another, you are likely to find more case in the group where you look more carefully, ”English mentioned.

Why have EU countries stopped using the vaccine?

Austria suspended a batch of Oxford / AstraZeneca vaccine as early as March 7 after one woman died and another fell ill after being vaccinated – both citing problems with blood clotting. Other European countries have followed suit, first by suspending specific batches, then by limiting its use in the youngest. By the end of the month, at least nine EU countries had completely stopped using the vaccine in younger populations due to problems with blood clotting.

On March 31, however, the EMA said there was no evidence to support the restrictions, but the agency’s safety committee would continue to review the reports. The announcement led most EU countries to lift their restrictions.

But reports of blood clotting kept coming in. Reports in the UK went from 5 to 30 in a week from March 24. Canada, which has not reported any problems with blood clotting, also suspended the vaccine in people under 55 when it ended. of March, citing disturbing reports from Europe.

Where is the EU now?

While most of the countries that suspended the use of jabs reversed their decisions when the EMA gave the cautious green light on March 18, several Nordic countries, along with France, took a more cautious approach and continued. at least partial suspensions.

In Finland, a full suspension only started after the announcement of the EMA, after two cases of blood clots in the brain. Its National Institute for Health and Welfare said on March 24 that they would only use the vaccine for people over 65 while investigations continue. Iceland also did not fully restart vaccination with the jab, limiting its use to over 70 years. Sweden has only resumed the vaccine for the 65 and over age group, with France allowing people aged 55 and over to access the vaccine. Estonia also recommended prioritizing the jab for those over 60.

Norway and Denmark continued the outright suspension of the coup, with Denmark announcing on March 25 that it would extend the ban for another three weeks.

Germany then launched a second wave of restrictions, announcing on March 30 that after 31 cases of blood clots in the brain, it would limit jab use to those under the age of 60. North Macedonia followed suit the next day, and the Netherlands followed suit on April 2. The Slovenian Immunization Advisory Group recommended a similar approach.

Why don’t we all stop using the vaccine?

Despite growing evidence that the Oxford / AstraZeneca vaccine is linked to these rare blood clotting conditions, the vaccine has clearly prevented thousands of people from ending up in hospital or dying from COVID-19. Public Health England, for example, estimated that the nearly 18 million Oxford / AZ jabs used at the end of March prevented more than 6,100 deaths in people over 70.

The World Health Organization said again Tuesday that there was “no link” between the vaccine and blood clotting events.

“At this time, there is no evidence that the benefit-risk assessment of the vaccine needs to be changed and we know from data from countries like the UK and others that the benefits are really significant. in terms of reducing mortality in vaccinated populations, ”said Rogerio Pinto de Sá Gaspar, director of the WHO regulatory and prequalification unit.

Gaspar concluded that we “tend to overemphasize the risk” rather than the benefit of the vaccine.

EMA’s Cavaleri was also clear when asked if “the risk-reward relationship still favors the vaccine.” He answered with a clear “yes”.

“This week we will start to define some preliminary definitions, but it is unlikely that we will indicate age limits as various countries have done,” Cavaleri said.

The agency will then carry out a more detailed analysis of the different population groups.

Regardless of what the EMA says this week, each country in the EU could end up making their own decision.

“The public health agencies that run the various vaccination campaigns have different options and can use them as they see fit,” Cavaleri said. “Many expect EMA to solve the problem for everyone, but it’s not that simple.”

In the UK, meanwhile, “no decision has yet been taken on any regulatory measure,” according to the MHRA. “People should continue to get vaccinated when prompted to do so.”


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