In his column April 9 ("Don't Cut Immunizations"), William Raspberry criticized the recent budget cuts in federal programs to immunize children against such diseases as polio, measles and tetanus. On April 11, George Will said many of the same things ("A Shot in the Arm"). On April 17 ("One Virulent Attack"), Health and Human Services Secretary Richard Schweiker replied with a defense of the administration's policies on immunization.

That reply was filled with misleading numbers of dollars and diseases and with illustrations as confused and mistaken as the president's comments to which Will referred. The secretary looked at measles cases from five years ago, but he was unwilling to compare last year's budget with this year's. He cited the nation's high immunity rates, but did not discuss the efforts that are needed to maintain them.

Since the discussion of the Reagan cuts in the immunization program originated in hearings before my subcommittee, I feel I must respond to the secretary's comments.

Childhood diseases were once common in America; today most school-age children are protected against such illness largely because of the federal childhood immunization program. Most children have received the 12 doses of vaccine that are recommended by the Advisory Council on Immunization Practices.

But last year, the administration proposed that this program be cut back by 34 percent, a cut that the Centers for Disease Control estimated would reduce their purchase of vaccine from 16 million doses to 8 million and cut in half the number of children immunized.

In writing legislation last year, Congress did not accept the president's proposal. But funding for 1982 was cut 10 percent below the 1981 level. This cut, combined with the 30 percent increase in the cost of vaccine, will mean that the federal government can provide only about 11 million doses of vaccine, a third less than in 1981.

Schweiker said that doesn't matter, that since most children who are now 6 years old are immunized, we don't need as much money. He is wrong.

Somehow he has overlooked the fact that children are born each year and that they, too, need to be protected against polio and rubella. While Schweiker is correct when he says that immunity levels are now high, he is mistaken in assuming that they will stay high without effort. Funds that are cut from the program not only cut the "catch-up" efforts for school-age children who aren't protected, but also cut deeply into "maintenance" programs to vaccinate newborns and keep immunity levels high.

Some basic arithmetic may help: about 3.5 million babies are born annually. Each of those children will need 12 shots. Only about half will receive their shots from private doctors. Thus, in order to keep up with newborns alone, we need 21 million doses of public vaccine each year. (If we are to give shots to those other 3.2 million school-age children that even Schweiker notes are still not immunized, we will need considerably more vaccine.)

Despite this continuing need and the continuing rise in the costs of vaccines, the administration suggests that we can somehow make do with effectively 30 percent less.

But Dr. Frederick Robbins, president of the Institute of Medicine and winner of the Nobel Prize for his work in polio, testified before my subcommittee that "although we have come close to eliminating polio from this country, we cannot relax our vigilance and we must continue to provide for the immunization of our children or new epidemics will become not only possible, but probable."

Another public health expert has already said that we can expect substantial upturns in measles and rubella "easily in a year or less," and that "in a couple of years we would begin to see increased rates of polio."

I am certain that the Centers for Disease Control will continue to do whatever they are given the money to do. I also appreciate the secretary's sincerity in promising that his department will monitor outbreaks of disease.

But I cannot accept the suggestion that we wait until an epidemic strikes to start buying vaccine. We cannot allow children to die of diseases that should never occur, and we cannot afford to treat children for crippling conditions that we can prevent. The fight against preventable diseases has not been won; there is no such thing as a truce with polio. To maintain immunity levels, we must start again every year.