Polls.vue

<template>
<!-- ...html -->
</template>

<script>
// ... code
import { OPTION_VOTED, POLL_CREATED } from '@/gql/subscriptions/poll.subscriptions'

// ... code

export default {
  // ... code

  apollo: {
    polls: {
      query: POLLS,
      subscribeToMore: [
        {
          document: OPTION_VOTED,
        },
        {
          document: POLL_CREATED,
          updateQuery(previousResult, { subscriptionData }) {
            return {
              polls: [
                subscriptionData.data.pollCreated,
                ...previousResult.polls,
              ]
            }
          }
        }
      ]
    }
  },

  // ... code
}
</script>