Shares of AstraZeneca (AZN 1.12%) are under pressure again following an analyst downgrade. Concerns about the pharmaceutical company's coronavirus vaccine led Argus Research to lower its rating on the stock from buy to hold on Monday morning.

Last Wednesday, the European Medicines Agency (EMA) said unusual blood clots with low blood platelets should be listed as a very rare side effect of AstraZeneca's COVID-19 vaccine, recently given the trade name Vaxzevria. The risk of death from COVID-19 is many orders of magnitude greater, but delays to Vaxzevria's European roll-out had already damaged public opinion regarding it. Across the EU and the U.K., around 34 million people have been vaccinated as of April 4, 2021. Over that period, 222 blood clots were reported to the EMA's side-effect hotline. The vast majority of those were non-fatal.

A scientist with great hair.

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Vaccine hesitancy in the EU and U.S. is already a problem, and the slightest hint of a dangerous side effect will make it more difficult, if not impossible, for AstraZeneca to earn significant profits from Vaxzevra. That said, since the company had already committed to selling the vaccine at cost during the pandemic, and on a permanent not-for-profit basis to low- and middle-income countries, AstraZeneca shareholders don't have much to worry about in terms of lost profits from Vaxzevra over the long run anyway.

The roll-out of this particular COVID-19 vaccine has been a disappointment, but investors need to remember that AstraZeneca isn't a vaccine company. It's an oncology-focused drugmaker, and a highly successful one with rapidly rising profits.

Unless cancer patients suddenly begin caring about who markets their therapies, COVID-19 vaccine hesitancy isn't going to appreciably impact AstraZeneca's earnings. The company's product lineup sports a handful of recently approved treatments that could push the company's bottom line and its stock price steadily higher for years to come.