Pfizer beat Wall Street expectations for the second quarter and raised its 2015 forecast, as sales of several products helped inoculate the world's second-largest drugmaker against revenue hits from a stronger U.S. dollar and cheaper generic competition.

Shares of the New York company started climbing Tuesday shortly after it released results.

Pfizer drew on 37 percent revenue growth from Prevnar 13, the world's top-selling vaccine, to help counter a $1 billion topline hit the drugmaker took due to foreign exchange rates. Prevnar 13 brought in $1.5 billion in sales during the quarter, and Pfizer is gearing up to squeeze more out of that category.

Vaccines are one of Pfizer's core research areas, and the drugmaker has expanded its work there with the goal of essentially protecting customers from cradle to grave.

Pfizer also brought in $140 million in the second quarter from Ibrance, a breast cancer treatment approved earlier this year by regulators. That topped the expectations of several analysts.

On the flip side, worldwide revenue from the painkiller Celebrex sank 71 percent to $224 million, as generic competition in the U.S. market chipped away at sales. Competition from cheaper, generic alternatives also hit the antibiotic Zyvox, which saw sales drop 26 percent to $259 million.

Sales of the fibromyalgia treatment Lyrica slid 7 percent to $1.22 billion.

Overall, Pfizer Inc.'s net income fell 10 percent to $2.63 billion from $2.91 billion. Earnings, adjusted for one-time gains and costs, totaled 56 cents per share in the most recent quarter.

That beat average analyst expectations for 51 cents per share, according to Zacks Investment Research.

Revenue fell 7 percent to $11.85 billion but still topped the average analyst forecast of $11.41 billion.

Excluding the impact from currency rates, Pfizer said revenue grew 1 percent in the quarter.

Pfizer now expects 2015 adjusted earnings of $2.01 to $2.07 per share, up from its previous forecast for $1.95 to $2.05 per share.

Analysts forecast, on average, earnings of $2.06 per share, according to FactSet.

Pfizer stock climbed 20 cents to $34.54 shortly after markets opened Tuesday, while broader indexes were nearly flat.

Shares of the drugmaker, a company used in calculating in the Dow Jones industrial average, have climbed 10 percent since the beginning of the year, while the Standard & Poor's 500 index has stayed nearly flat. The stock has risen 14 percent in the last 12 months.