CSL (ASX:CSL) share price wobbles on COVID vaccine news

The CSL Limited (ASX: CSL) share price is on watch after the UK found "possible links" between the AstraZeneca vaccine and blood clots.

| More on:
A man looking sheepish grits his teeth and looks to the side

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More

The CSL Limited (ASX: CSL) share price is a little wobbly this morning after negative vaccine news overnight from the United Kingdom.

The pharmaceutical giant, which produces and supplies the AstraZeneca PLC (LSE: AZ) COVID-19 vaccine in Australia, is trading close to its opening price after news that the UK medical regulator has found a "possible link" between the vaccine and blood clotting in younger adults. The regulator noted that blood clotting was considered a rare side-effect of the vaccine.

At the time of writing, the CSL share price is trading flat around $263 as Australian investors digest the news out of the UK.

What's driving the CSL share price?

The Medicines and Healthcare products Regulatory Agency (MHRA) released a statement overnight concluding the evidence of a causal link between blood clotting and receiving the AstraZeneca vaccine in low platelet individuals was stronger than previously thought, but not conclusive.

The agency said the risk of blood clotting decreased with age and was "extremely rare and unlikely to occur". 

Its statistics suggested the risk of developing a blood clot after the first vaccine dose was 1 in 250,000 (0.0004%) and the risk of a fatal blood clot was 1 in 1 million (0.0001%). Despite this, the UK will provide alternative vaccines to the under 30s if possible.

The World Health Organisation (WHO) responded to the UK news, saying evidence of the link, while plausible, was not yet confirmed. It also noted the risk of catching and dying from COVID-19 was much higher than the risk of the vaccine.

What did our top doctor say?

Australia's chief medical officer, Professor Paul Kelly told ABC Radio:

There seems to be a trend in younger people and, at least in the European data in women being more common, but I would really stress these are extremely rare events and like with any treatment… we have to look at the risk and benefit.

And we do know that the benefits of vaccinations against this very serious diseases Covid is a really important component of our control…

Ultimately it will be a decision by the Australian Government about what that means for the vaccine rollout.

Australia's position

Australia is primarily relying on the AstraZeneca vaccine in the fight against COVID. The government has contracted CSL to develop the vaccine locally.

Both the imported and locally manufactured AstraZeneca vaccine have already been approved by the Therapeutics Good Administration (TGA).

Speaking about the developments this morning, Prime Minister Scott Morrison said Australia's medical experts would look at the data before making new recommendations to the government.

The Prime Minister also stressed the extremely low chances of people experiencing blood clotting from the vaccine. He advised that at present, the vaccine rollout would not be affected by the latest developments.

Motley Fool Australia reached out to CSL for comment, but none was received before publication.

Wondering where you should invest $1,000 right now?

When investing expert Scott Phillips has a stock tip, it can pay to listen. After all, the flagship Motley Fool Share Advisor newsletter he has run for over ten years has provided thousands of paying members with stock picks that have doubled, tripled or even more.*

Scott just revealed what he believes could be the 'five best ASX stocks' for investors to buy right now. We believe these stocks are trading at attractive prices and Scott thinks they could be great buys right now...

See The 5 Stocks *Returns as of 30 April 2025

Marc Sidarous has no position in any of the stocks mentioned. The Motley Fool Australia's parent company Motley Fool Holdings Inc. owns shares of CSL Ltd. The Motley Fool Australia has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Bruce Jackson.

More on Share Market News

A woman's hand draws a stylised 'Top Ten' on a projected surface.
Share Gainers

Here are the top 10 ASX 200 shares today

ASX shares returned to positive territory this Tuesday.

Read more »

Multiple percentage signs in the palm of a man's hand.
Share Market News

ASX 200 lifts on the RBA's latest interest rate call

The ASX 200 is up 0.5% on the heels of the RBA’s interest rate announcement.

Read more »

Man drawing an upward line on a bar graph symbolising a rising share price.
Broker Notes

Macquarie tips 40% upside for this ASX 200 real estate stock

Let's see what the broker is saying about this stock.

Read more »

Woman sits at her desk working at night, while traffic flows on a busy freeway out the window behind her.
Broker Notes

Transurban shares: Buy, hold, sell? Here's Macquarie's recommendation

Macquarie’s analysts just ran their slide rules over Transurban shares. Here’s what they found.

Read more »

A woman sits at her home computer with baby on her lap, and the winning ticket in her hand.
Consumer Staples & Discretionary Shares

Which 'enduring high-quality business' has become a forgotten ASX 200 stock?

Fundie says this ASX 200 consumer discretionary stock has been flying under investors' radar.

Read more »

A woman sits at her computer with her chin resting on her hand as she contemplates her next potential investment.
Financial Shares

Want a financial stock outside the big 4 banks? Macquarie tips 15% upside for this small cap financial

For those searching on the edges, this name could be worth a second look according to Macquarie.

Read more »

A male investor wearing a blue shirt looks off to the side with a miffed look on his face as the share price declines.
Share Fallers

Why Kogan, Monash IVF, OFX, and ResMed shares are falling today

Why are these shares taking a tumble today? Let's find out.

Read more »

Overjoyed man celebrating success with yes gesture after getting some good news on mobile.
Share Gainers

Why Breville, Clarity, EOS, and TechnologyOne shares are racing higher today

These shares are having a strong session on Tuesday. But why?

Read more »