Pfizer (PFE 0.11%)had a fine first quarter by many standards. Fueled by widespread demand for its BNT162b2 coronavirus vaccine, it crushed both trailing and forward analyst estimates.

One prognosticator following the company, however, isn't ready to pop the Champagne. On Thursday -- two days after those quarterly results were published -- Vamil Divan of Mizuho Securities downgraded his recommendation on the stock from buy to neutral. He maintained his $42 per share price target, which is about 7% above where it's currently trading.

A researcher studying a sample in a petri dish.

Image source: Getty Images.

The analyst credited Pfizer with a "stunning beat" in his new research note. However, he wrote, "Cash flows from COVID-19 vaccine sales provide Pfizer with greater optionality, but we wait to see how Pfizer allocates that capital before assessing whether they have improved their 2026-2030 outlook."

As with any pharmaceutical company, Pfizer's future depends greatly on its pipeline. Since much of the focus on Pfizer as a company and as a stock has, understandably, been on BNT162b2 over the past year, more attention needs to be paid to its research and development activities.

"While Pfizer's near-term outlook remains strong and has been boosted by their COVID-19 vaccine, we believe it will be important for these pipeline catalysts to deliver in the coming months in order for investors to gain more comfort with Pfizer's outlook beyond the next four years and drive Pfizer shares meaningfully higher," Divan wrote.

BNT162b2 is currently in widespread use in countries around the world, and particularly in the U.S., where it is one of only three coronavirus vaccines authorized for emergency use by the FDA. However, both cases and fatalities have been dropping significantly in the country.

Pfizer's shares closed Thursday's trading session down by 1%, against the 0.8% rise of the S&P 500 index.