I have been combing through public health campaigns in India post Independence, highlighting pivotal product designs and creating a timeline of graphic design used for dissemination over the years.
Will be sharing bits of these over the next few days!

Starting with Smallpox:
In the early 1960s, India accounted for roughly 60% of the world's reported Small Pox cases. 1962, India launched National Smallpox Eradication Program (NSEP) focusing on mass vaccination.

By 1966, around 60 million primary vaccinations were administered, however the number of cases continued to rise.
India, being complex and vast, can attribute this failure to many things including communal unrest, various types of inaccessibility and general distrust.

In 1967, while smallpox was still endemic in 50 countries, WHO Scientific Group on Smallpox Eradication convened in Geneva and began more concerted efforts towards global eradication. This included deploying assessment teams and other resources to endemic countries like India.

1969 Smallpox poster from Maharastra, talking about the symptoms of smallpox- rashes, blindness and death.

Thanks to @mycrotchetyluv for helping take apart this one!

Superstition and stigma was the primary reason cases went unreported in India, once WHO stepped in they began incentivising reporting of smallpox cases.

Another big reason mass vaccination failed was the quality of the vaccine and the way in which it had to be administered. Prior to 1969, a drop of the vaccine was placed on the patient's arm and pressed into the skin with a single point needle.

This process had to be repeated 5 times for primary vaccination and 15 times for revaccinations- which required a lot of trained personnel and meant that a lot of the liquid would get wasted.

With the introduction of bifurcated needles and a better quality vaccine that could be freeze-dried, in 1967, the entire process was made more simple and efficient.

GOI handbooks highlighting the developments in the immunisation process.

Smallpox has a special place in medical history; it was the first disease to have a vaccine developed and still the only disease that has been eradicated by vaccination. The development of the smallpox vaccine is a fascinating story itself that spans over centuries.

Following the replacement of rotary lancet with the bifurcated needle technique and it's success, India began "search & contain" efforts on a massive scale; deploying teams to settlements across India to identify cases, isolate infected individuals & vaccinate community members.

Health workers were tasked with tedious documentation of cases. It was estimated that roughly 8 tons on paper were used in this process. (Jonathan Tucker, Scourge: The Once and Future Threat of Smallpox)

By 1973, these efforts were showing promising success and smallpox cases in India were mostly limited to the states of UP, Bihar and West Bengal.
The Govt. of India threw it's full weight behind surveillance and containment of the disease.

During the final phase, in the early 70s in India, the Global Smallpox Eradication Programme focused on zero smallpox incidence.
Healthcare workers in the field were given kits and handouts to help identify and record cases in settlements across the remaining endemic states.

Alongside all of this, the vaccine and its method of administration had been developing as well.
In the 1950s, American physician Robert Hingson had designed a "jet injector" that did not require needles and painlessly administered injections.

Hingson's piston propelled injector was not ideal for smallpox & the challenges of mass vaccination for two reasons- 1. it required electricity to run 2. it could only administer injections subcutaneously (under the skin) but the smallpox vaccine had to be intradermally injected.

In 1959, Aaron Ismach developed a version of the jet-injector that was hydraulically powered and pedal operated, he also patented a nozzle that could administer the vaccine intradermally and around 1000 times/hour.
Patent technical drawing of 'multi-dose jet injection device.'

Through the 60s this device was tested in Brazil and eventually brought over to India and used in the search and contain efforts by the 70s.

--This thread was interrupted by poor laptop health, but I'm back now!--
Aaron Ismach's patented intradermal nozzle and Hingson's jet injector was tested in Brazil in the 60s and was wildly successful and the last case of smallpox in the Americas was declared in Brazil in '71.

The updated jet injector was brought over to India in the early 70s and dubbed "shanti ki handuk."
Image: An early 70s ad for the new simple and straightforward method of vaccination.